BACKGROUND OF THE INVENTION
[0001] The present invention relates to a device and a method for controlling feed of lap
in a comber.
[0002] The comber has a plurality of combing heads each having a combing cylinder. Lap fed
from lap roll is gripped by a nipper device located at its retracted position and
combed at the front end thereof by the combing cylinder to remove short fibers from
the lap, thus forming fleece. The fleece is moved toward a pair of detaching rollers
by forward movement of the nipper device. In accordance with the forward movement
of the fleece, the paired detaching rollers are rotated in reverse direction thereby
to move back the previous fleece. Thus, the rear end of the previous fleece and the
front end of the newly combed fleece (following fleece) are lapped one on another.
When the paired detaching rollers are rotated in forward direction, the fleece is
removed from the nipper device. In addition, the following fleece and the previous
fleece are joined together and the rear end of the following fleece is combed by top
comb. The fleece fed by each combing head is bundled into sliver. The stivers formed
by the respective combing heads are bundled into a single strand of sliver, drafted
by drafting part and stored in a sliver can by coiler mechanism. Thus, the comber
is operable to produce a sliver from the lap wound in the form of a lap roll.
[0003] Due to the change of diameter of the lap roll from a full lap roll where consumption
lap length of lap roll is zero to an empty roll where consumption lap length of lap
roll is 100%, the weight of feed lap of the same length varies. If the comber is operated
at a constant lap feed speed, therefore, the weight of the sliver for a given length
thereof varies greatly.
[0004] To prevent the above variation of the sliver weight, Japanese Unexamined Patent Application
Publication (Japanese translation of
PCT international Application) No. 6-502894 suggests a method of correcting the variation of weight of lap due to the change
of diameter of lap roll by increasing lap feed speed in the process of combing operation
from the full lap roll to the empty roll. To control the lap feed speed, the above-cited
reference discloses a method of determining controlled variable of driving speed of
a pair of lap rollers (or a pair of lap arbors) on which the lap roll is placed, in
accordance with the deviation of the measurements of a device that measures lap feed
weight or the sliver weight. The above-cited reference also suggests a method of increasing
the lap feed speed in a linear and continuous fashion from the beginning of lap feeding
(open-loop control) without measuring the lap feed weight or sliver weight.
[0005] In order to determine controlled variable of the driving speed in accordance with
the deviation of the measurements of lap feed weight or sliver weight, there needs
to be a device that measures the lap feed weight or sliver weight. However, such device
is large in size and hence increases the cost of the comber. In addition, measuring
the sliver weight is disadvantageous in terms of accuracy because the measuring point
of the sliver weight is spaced far away from the lap roll and also in that the amount
of waste cotton needs to be considered.
[0006] The method by the open-loop control that dispenses with the measuring step is disadvantageous
in terms of the controlling accuracy because the sliver weight does not simply decrease
in accordance with a decrease of lap roll diameter.
[0007] The present invention is directed to providing a device and a method for controlling
feed of lap in a comber according to which variation of sliver weight due to the change
of lap roll diameter is corrected effectively without using a device for measuring
the weight of lap or sliver thereby to equalize the sliver weight or reduce the variation
of the sliver weight.
SUMMARY OF THE INVENTION
[0008] As a result of research for the relationship between the change of the lap roll diameter
and the variation of the sliver weight, the present inventors found that the variation
of the sliver weight due to the change of the lap roll diameter is generally reproducible
and also that the variation of the sliver weight due to the change of the lap roll
diameter is obtained by manually measuring the finished sliver weight. The present
invention has been made based on such findings. It is noted that the term "finished
sliver weight" means the weight of the sliver made by all the laps supplied from lap
rolls of a plurality of combing heads of a comber.
[0009] In accordance with a first aspect of the present invention, there is provided a lap
feed control device for controlling feed of lap in a comber. The comber is operable
to produce a sliver from the lap wound in the form of a lap roll and has a plurality
of combing heads each having a lap feeder. The lap feeder has a motor that can be
driven independently of a combing drive device. The lap feed control device is characterized
in that the lap feed control device includes an arithmetic-logic unit and a control
unit. When the comber is operated with the motor driven at a constant speed on a trial
basis, variation of weight of the sliver relative to decrease of diameter of the lap
roll is measured. The arithmetic-logic unit calculates a speed change pattern of the
motor from the measurements of the variation of the weight of the sliver to equalize
the weight of the sliver or reduce the variation of the weight of the sliver. The
control unit controls operation of the motor of the lap feeder in accordance with
the speed change pattern.
[0010] It is noted that the term "speed change pattern" is not limited to a pattern that
represents speed change of motor directly, but also refers to a pattern according
to which speed change ratio is changed.
[0011] In accordance with a second aspect of the present invention, there is provided a
lap feed control method for controlling feed of lap in a comber. The comber is operable
to produce a sliver from the lap wound in the form of a lap roll and has a plurality
of combing heads each having a lap feeder. The lap feeder has a motor that can be
driven independently of a combing drive device. The lap feed control method is characterized
by the steps of measuring weight of the sliver for each predetermined length while
operating the comber with the motor driven at a constant speed on a trial basis, calculating
a speed change pattern of the motor from the measurements of the weight of the sliver
in view of change of lap roll diameter to equalize the weight of the sliver or reduce
the variation of the weight of the sliver, and controlling operation of the motor
of the lap feeder in accordance with the speed change pattern.
[0012] Other aspects and advantages of the invention will become apparent from the following
description, taken in conjunction with the accompanying drawings, illustrating by
way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention together with objects and advantages thereof, may best be understood
by reference to the following description of the presently preferred embodiments together
with the accompanying drawings in which:
Fig. 1 is a schematic side view showing a combing head of a comber according to an
embodiment of the present invention;
Fig. 2 is a graph showing the relation between consumption lap length and sliver weight;
and
Fig. 3 is a graph showing the relation between the consumption lap length and speed
change factor.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The following will describe the comber according to the embodiment of the present
invention with reference to Figs. 1 through 3. The comber has a plurality of combing
heads 11 (eight combing heads in the present embodiment), one of which is shown in
Fig. 1. It is noted that the left-hand side and right-hand side of Fig. 1 correspond
to the front and the rear of the combing head 11, respectively. Referring to Fig.
1, the combing head 11 includes a pair of lap rollers 12, a nipper device 14, a combing
cylinder 15 and two pairs of detaching rollers 16, 17. The nipper device 14 has a
feed roller 13 and the paired detaching rollers 17 are located forward of the paired
detaching rollers 16.
[0015] The nipper device 14 has a nipper frame 18 that is pivotally supported by a shaft
23A so as to be swingable back and forth and disposed above the combing cylinder 15.
The nipper frame 18 has at the bottom thereof a bottom nipper 19. A nipper arm 20
is pivotally supported by a shaft 18A mounted to the nipper frame 18. A top nipper
20A is fixed to the distal end of the nipper arm 20. The top nipper 20A is operated
to be opened and closed at a predetermined time in synchronization with the back-and-forth
movement of the nipper frame 18 thereby to hold lap in cooperation with the bottom
nipper 19. A top comb 21 is mounted to the nipper frame 18 at a position that is forward
of the bottom nipper 19 and operable to move in synchronization with the nipper frame
18.
[0016] A reciprocally rotatable nipper shaft 22 is located at a position that is behind
the combing cylinder 15 and below the nipper frame 18. The rear end of the nipper
frame 18 is pivotally supported by the shaft 23A at the distal end of a nipper frame
drive arm 23 whose proximal end is fixed on the nipper shaft 22 for rotation therewith.
The nipper frame 18 is swingable back and forth by the reciprocal rotation of the
nipper shaft 22 so that the front end of the bottom nipper 19 is moved toward and
away from the detaching rollers 16, 17. The comber includes a drive shaft (not shown)
that is common to all the combing heads 11 and driven by a main motor 24, and the
rotation of the drive shaft is transmitted to the combing cylinder 15, the nipper
shaft 22 and the detaching rollers 16, 17 via a power transmission device 25 such
as transmission gear or crank mechanism. The nipper device 14 is driven in synchronization
with the combing cylinder 15. The main motor 24 and the power transmission device
25 cooperate to form the combing drive device of the present invention.
[0017] The comber further includes a lap roller drive shaft (not shown) that is common to
all the combing heads 11 and driven by a lap roller drive motor 26 to drive a lap
roller shaft 12A of the lap roller 12 via a belt transmission device 27. The lap roller
shaft 12A is driven independently of the main motor 24. The lap roller drive motor
26 serves as the motor of the present invention and can be driven independently of
the combing drive device. The main motor 24 and the lap roller drive motor 26 are
driven via inverter devices 29 and 30, respectively, that are controlled by command
of a control device 28. The lap roller 12, the lap roller shaft 12A, the lap roller
drive motor 26 and the belt transmission device 27 cooperate to form the lap feeder
of the comber of the present invention.
[0018] The control device 28 includes a central processing unit (CPU) 31, a memory 32, and
an input and display device 33. The CPU 31 is operated in accordance with program
data stored in the memory 32. The input and display device 33 has a touchscreen that
allows input of data by touching any input area displayed on its display screen. The
input and display device 33 serves as both input device and display device. The input
and display device 33 is used for inputting data representative of various combing
conditions of the comber, such as the type of fiber to be combed (or fiber length),
weight of sliver, number of nips, and any other data.
[0019] The following will describe the control device 28 that serves as the lap feed control
device in the comber. The input and display device 33 is also used for inputting the
measurements of weight of sliver (finished sliver weight). The memory 32 serves not
only as an input unit of the measurements of the sliver weight, but also as a storage
unit for data of speed-change pattern of the lap roller drive motor 26 calculated
by the CPU 31. The CPU 31 serves not only as an arithmetic-logic unit that calculates
the speed change pattern of the lap roller drive motor 26 from the measurements entered
in the input unit of measurements of the sliver weight, but also as a control unit
that controls the operation of the lap roller drive motor 26 in accordance with the
speed-change pattern calculated by the arithmetic-logic unit and stored in the memory
unit.
[0020] The CPU 31 calculates the speed change pattern of the lap roller drive motor 26 from
the measurements of the sliver weight entered in the memory 32 and stores data of
the calculated speed change pattern in the memory 32. The CPU 31 regards the speed
change ratio as 1/weight ratio in calculating the speed change pattern. It is noted
that the term "speed change ratio" means the changed speed/reference speed, and also
that the term "weight ratio" means (the sliver weight determined at a lap roll diameter
when speed is changed) / (the sliver weight at a reference lap roll diameter).
[0021] The program according to which the CPU 31 calculates the speed change pattern is
subject to the action of a filter that blocks the variation of the sliver weight that
is not caused by the change of the lap roll diameter in calculating the speed change
pattern from the measurements entered in the memory 32. That is, the arithmetic-logic
unit has the filter for the entered measurements and the filter is operable to block
the variation of the sliver weight in a range that is less than unit length of the
sliver (9.144 meters or 10 yards in the present embodiment). The unit length of the
sliver is appropriately settable.
[0022] The following will describe the operation of the control device 28. When the comber
is manufactured in a factory, data of the speed change pattern that equalizes the
sliver weight or reduces the variation of the sliver weight in view of the change
of the lap roll diameter is not stored in the memory 32. The lap roller drive motor
26 is driven at a constant speed corresponding to the speed of the combing cylinder
15. In order for the CPU 31 to calculate the speed change pattern that equalizes the
sliver weight or reduces the variation of the sliver weight in view of the change
of the lap roll diameter, the comber is operated with the lap roller drive motor 26
driven at a constant speed on a trial basis. During this trial operation, the sliver
weight is measured by workman. This step corresponds to the step of measuring the
weight of the sliver of the present invention. The measurements of the weight are
inputted into the memory 32 using the input and display device 33 and stored in the
memory 32. This step corresponds to the step of inputting the measurements of the
weight of the sliver.
[0023] It is difficult to indicate the measurements so as to correspond to the lap roll
diameter because it is difficult to detect the change of the lap roll diameter accurately.
Thus, consumption lap length is used in place of the lap roll diameter. The relation
between the consumption lap length and the sliver weight is shown by the graph of
Fig. 2, wherein the horizontal axis of the graph represents the consumption lap length
and the vertical axis represents the sliver weight. When the consumption lap length
is zero, the lap roll is full. As the consumption lap length increases, the lap roll
diameter decreases. The vertical axis of the graph does not represent the sliver weight
directly, but it shows the weight in percentage. Specifically, the vertical axis represents
the sliver weight in percentage wherein the sliver weight is 100% when the consumption
lap length is zero. Fig. 2 suggests that the sliver weight is not simply proportional
to the lap roll diameter, but varied in a complicated manner.
[0024] The CPU 31 calculates the speed change pattern from the relation between the sliver
weight stored and the consumption lap length in the memory 32. This step corresponds
to the step of calculating speed change pattern of the present invention. The graph
of Fig. 2 is filtered and smoothened by the CPU 31. In filtering the graph of Fig.
2, if the unit length of the sliver is 10 yards or more, the accuracy of the arithmetic-logic
unit is reduced. If the unit length of the sliver is too short, the number of data
is increased and additional work is required.
[0025] The CPU 31 calculates speed change factor (indicated by percentage) for the consumption
lap length x using the following equation:

[0026] In the present embodiment, when the CPU 31 calculates the speed change pattern, reference
lap feed speed used in calculating the speed change ratio is used as lap feed speed
when the consumption lap length is 0%.
[0027] A manner of changing of the speed change factor during combing operation from the
state of full lap roll (consumption lap length being 0%) to the time for replacement
of the lap roll L (consumption lap length being 100%) is shown by the graph of Fig.
3. The horizontal axis of the graph of Fig. 3 represents the consumption lap length
(indicated in percentage) and the vertical axis represents the speed change factor
(indicated in percentage) with respect to the lap feed speed when the consumption
lap length is zero. Thus, the curve of Fig. 3 shows speed change pattern for the consumption
lap length.
[0028] The speed change pattern has a plurality of transition points (nine transition points
in the present embodiment) and a plurality of sections (eight sections in the present
embodiment) divided by the transition points. The transition points correspond to
the consumption lap lengths previously entered by the input and display device 33,
respectively. The speed change factor is set for each transition point. The intervals
between any two adjacent transition points (or the sections) have different lengths.
In the range for a section where the change of the sliver weight is relatively large
with respect to the consumption lap length, the section is set relatively short. In
the range for a section where the change of the sliver weight is relatively small
with respect to the consumption lap length, the section is set relatively long. The
position of the transition point, or the consumption lap length (%) of the transition
point, may be set by manually inputting the data through the input and display device
33.
[0029] The CPU 31 calculates speed change factors for the respective consumption lap lengths
of the transition points and stores data for the relation between the consumption
lap length of each transition point and the speed change factor for the consumption
lap length in the memory 32, as shown in Table 1 below. This step corresponds to the
step of storing speed change pattern.
Table 1
transition point |
consumption lap length (%) |
speed change factor (%) |
0 |
0 |
100.0 |
1 |
5 |
101.5 |
2 |
10 |
101.9 |
3 |
20 |
101.9 |
4 |
30 |
102.3 |
5 |
60 |
102.5 |
6 |
90 |
103.6 |
7 |
95 |
103.0 |
8 |
100 |
101.4 |
[0030] In the speed change pattern of Table 1, the CPU 31 calculates the speed change factor
between any two adjacent transition points based on the value of the speed change
factor of the transition points. In the present embodiment, the speed change factor
between any two adjacent transition points is calculated from the gradient of a straight
line connecting the transition points.
[0031] The speed change pattern shown in Fig. 3, wherein the speed change factor is 100%
when the consumption lap length is 0%, is represented by the relation between the
consumption lap length and the speed change factor for the consumption lap length.
The speed change factor corresponds to a value that indicates a speed change ratio
in percentage. That is, the speed change pattern has a plurality of transition points
and a plurality of sections divided by the transition points. The speed change ratio
is set at each transition point and the speed change ratio between any two of the
adjacent transition points is set in accordance with the speed change ratios of the
two adjacent transition points.
[0032] The following will describe a manner of controlling the lap roller drive motor 26
of the lap feeder by the control device 28. Replacement of the lap rolls L of the
comber is performed simultaneously for all the combing heads 11. The replacement of
an empty roll with a full lap roll L is detected by the control device 28 via manual
operation or automatic detector. The control device 28 detecting the replacement resets
the consumption lap length (%) to zero and is set to its initial state.
[0033] After the combing operation is restarted, the control device 28 controls the speed
of the lap roller drive motor 26 via the inverter device 30 in accordance with the
speed change pattern stored in the memory 32. This step corresponds to the step of
controlling motor of the present invention. The CPU 31 calculates the consumption
lap length by integrating the motor speed corresponding to indicated frequency of
the lap roller drive motor 26 by time. The reference speed of the lap roller drive
motor 26 corresponding to 100% of speed change factor is set previously.
[0034] The speed changing of the lap roller drive motor 26 is accomplished by multiplying
the reference speed by speed change factor (%) at consumption lap length x% corresponding
to the time of speed change. Speed change point entered by the input and display device
33 includes only the starting point and the end point of the speed change pattern
and the transition points between the sections. However, the CPU 31 automatically
calculates the speed change factor between any two adjacent transition points from
fixed gradient of the straight line connecting the transition points, and uses the
speed change factor to calculate the speed of the lap roller drive motor 26 at each
consumption lap length x% thereby to direct the frequency corresponding to the above
speed of the lap roller drive motor 26 to the inverter device 30. By doing so, the
CPU 31 controls the operation of the lap roller drive motor 26.
[0035] When the combing condition of the comber under which speed change pattern is stored
in the memory 32 is changed, the comber is operated with the lap roller drive motor
26 driven at a constant speed under the present combing condition on a trial basis.
The CPU 31 calculates the speed change pattern corresponding to the combing operation
as described above and stores the speed change pattern in the memory 32. Thus, the
CPU 31 controls the operation of the lap roller drive motor 26 in accordance with
the speed change pattern corresponding to the combing operation.
[0036] The above-described embodiment offers the following advantageous effects.
- (1) The comber is operable to produce a sliver from the lap wound in the form of a
lap roll and has a plurality of combing heads 11 each having a lap feeder. The lap
feeder has a lap roller drive motor 26 that can be operated independently of a combing
drive device. The lap feed control device includes an arithmetic-logic unit (CPU 31)
and a control unit (CPU 31). When the comber is operated with the lap roller drive
motor 26 driven at a constant speed on a trial basis, variation of weight of the sliver
relative to decrease of diameter of the lap roll is measured. The arithmetic-logic
unit calculates a speed change pattern of the lap roller drive motor 26 from the measurements
of the variation of the sliver weight. The control unit controls the operation of
the lap roller drive motor 26 in accordance with the speed change pattern calculated
by the arithmetic-logic unit. Therefore, the comber corrects the variation of sliver
weight effectively due to the change of lap roll diameter thereby to equalize the
sliver weight or reduce the variation of the sliver weight without using a device
for measuring the weight of lap or sliver. Because no measurement device that requires
adjustment or calibration (or correction) is used in the lap feed control device,
no individual difference derivable from such adjustment or calibration occurs in the
combers, which is advantageous in a combing mill using a plurality of combers.
- (2) In calculating the speed change pattern of the lap feed speed, the arithmetic-logic
unit (CPU 31) regards the speed change ratio as K / weight ratio. The weight ratio
is represented by (sliver weight determined at a lap roll diameter when speed is changed)
/ (sliver weight at a reference lap roll diameter) and K is a proportional constant.
The proportional constant K is set at 1. Thus, if the sliver weight is not varied,
no change of the speed of the lap roller drive motor 26 occurs. If the sliver weight
is decreased relative to the sliver weight corresponding to the reference lap roll
diameter, the speed of the lap roller drive motor 26 is increased. Conversely, if
the sliver weight is increased relative to the sliver weight corresponding to the
reference lap roll diameter, the speed of the lap roller drive motor 26 is decreased.
Therefore, the variation of the sliver weight is appropriately reflected on the lap
feed speed.
- (3) The arithmetic-logic unit has a filter that is operable to block the variation
of the sliver weight in a range that is less than unit length of the sliver. Thus,
the variation of the sliver weight that is not due to the change of the lap roll diameter
is blocked by the filter when the arithmetic-logic unit calculates the speed change
pattern from the measurements of the variation of the sliver weight. As compared to
the case where the arithmetic-logic unit has no filter, equalization of the sliver
weight or reduction of the variation of the sliver weight can be performed more effectively.
- (4) The speed change pattern has a plurality of transition points and a plurality
of sections divided by the transition points. The speed change ratio is set at each
transition point. The speed change ratio between two of the adjacent transition points
is set in accordance with the speed change ratios of the two adjacent transition points.
The speed change ratio between the two adjacent transition points is calculated from
the gradient of a straight line connecting the two adjacent transition points by the
arithmetic-logic unit (CPU 31). Therefore, the speed change control of the lap roller
drive motor 26 is appropriately performed throughout the lap feed operation even when
the number of input data of speed change point necessary for calculating the speed
change pattern is few.
- (5) The speed change pattern is represented by the change of value of speed change
factor (%) relative to the consumption lap length (%). The speed change factor (%)
is represented by 100 * {1 / (sliver weight for the consumption lap length x / sliver
weight when the consumption lap length is zero)}. Therefore, when the speed change
pattern is shown in the drawing, the variation of the lap feed speed relative to the
consumption lap length is easily understandable.
- (6) In controlling the speed change of the lap roller drive motor 26 in accordance
with the speed change pattern stored in the memory 32, the CPU 31 calculates the consumption
lap length by integrating the motor speed corresponding to indicated frequency of
the lap roller drive motor 26 by time. Therefore, the CPU 31 can calculate the consumption
lap length without using any sensor for measuring the consumption lap length.
- (7) In the lap feed control method in a comber according to the present embodiment,
the sliver weight is measured for each predetermined length of the sliver while the
comber is operated with the lap roller drive motor 26 driven at a constant speed on
a trial basis. The speed change pattern of the lap roller drive motor 26 is calculated
from the measurements of the sliver weight by the arithmetic-logic unit (CPU 31) in
view of the change of lap roll diameter, thereby to equalize the sliver weight or
reduce the variation of the sliver weight. Operation of the lap roller drive motor
26 is controlled in accordance with the speed change pattern by the control unit (CPU
31). Therefore, the variation of sliver weight due to the change of lap roll diameter
is corrected effectively without using a lap weight measurement device or a sliver
weight measurement device, thereby to equalize the sliver weight or reduce the variation
of the sliver weight.
[0037] The present invention has been described in the context of the above-described embodiment,
but it is not limited to the embodiment. It is obvious to those skilled in the art
that the invention may be practiced in various manners as exemplified below.
[0038] The speed change pattern may be calculated according to the speed change ratio being
equal to K / weight ratio instead of the speed change ratio being equal to 1 / weight
ratio, where "K" means a proportional constant. It is noted that the value of the
proportional constant K calculated previously by test for material of lap is stored
in the memory 32. As compared to the case where the proportional constant K is set
at a constant value such as 1 regardless of the material of lap, the method according
to the present invention is effective to equalize the sliver weight or to reduce the
variation of sliver weight.
[0039] The lap feed speed (or lap roller speed) during the time when the consumption lap
length is other than zero may be set at the reference speed. In this case, the speed
change of the lap roller drive motor 26 differs from that in the case where the lap
feed speed when the consumption lap length is zero is set at the reference speed.
The speed of the lap roller drive motor 26 may be changed so as to decrease with respect
to the reference speed.
[0040] A device that measures consumption lap length may be provided in the comber so that
the speed change of the lap roller drive motor 26 is controlled in accordance with
the consumption lap length measured by the measuring device. For example, the lap
roller shaft 12A may be provided with a pulse generator that generates to the control
device 28 pulses that are indicative of the speed of the lap roller 12 and hence the
consumption lap length directly. Thus, the speed of the lap roller 12 may follow the
speed change pattern of the lap roller drive motor 26 with an increased accuracy.
Alternatively, the lap roller speed may be feedback-controlled. In these cases, further
accurate control may be achieved.
[0041] The speed change pattern of the lap roller drive motor 26 is not limited to the change
of the speed change factor relative to the consumption lap length. The speed change
pattern of the lap roller drive motor 26 may directly represent the speed change of
the lap roller drive motor 26 relative to the consumption lap length.
[0042] Although the speed change pattern of the lap roller drive motor 26 represents speed
change factor or speed change in relation to the consumption lap length as a substitution
for the lap roll diameter, it may represents speed change factor or speed change in
relation to the lap roll diameter. In this case, a sensor for detecting the lap roll
diameter is required.
[0043] The combing cylinder shaft 15A may be provided with a pulse generator that generates
to the control device 28 pulses that are indicative of the speed of the combing cylinder
shaft 15A, and the lap feed speed may be controlled in synchronization with the measured
speed of the combing cylinder shaft 15A. In this case, control with further increased
accuracy is achieved.
[0044] The control device 28 need not necessarily have a structure for calculating the speed
change pattern for controlling the speed change of the lap roller drive motor 26.
The control device 28 only needs to have a storage unit storing therein the speed
change pattern and a control unit that controls the operation of the lap roller drive
motor 26 in accordance with the speed change pattern stored in the storage unit. In
the present embodiment wherein the sliver weight is measured for each predetermined
length of the sliver while the comber is operated at a constant speed of the lap roller
drive motor 26 on a trial basis, a device provided independent of the comber may calculate
the speed change pattern of the lap roller drive motor 26 from the measurements of
the sliver weight in view of the change of the lap roll diameter. In this case, data
of the calculated speed change pattern is stored in the storage unit of the control
device 28 provided in the comber via any removable media such as USB memory or magnetic
optical disk. That is, the device used for the step of inputting the measurements
of the sliver weight and the step of calculating speed change pattern may be provided
separately from the comber. Calculating the speed change pattern based on the measurements
of the sliver weight may be performed by a personal computer.
[0045] The number of sections of the speed change pattern is not limited to eight, but may
be other than eight.
[0046] The interval between any two adjacent transition points of the speed change pattern
may be the same. In this case, the number of transition points should be preferably
increased so that the speed change pattern is made reflecting the change of the consumption
lap length in the range where a large variation occurs.
[0047] The control device 28 may calculate the speed change factor from the measurements
and provide the data of the calculated speed change factor to the lap feed control
unit without storing the data of speed change pattern in the memory 32.
1. A lap feed control device (28) for controlling feed of lap in a comber, wherein the
comber is operable to produce a sliver from the lap wound in the form of a lap roll
(L) and has a plurality of combing heads (11) each having a lap feeder (12, 12A, 26,
27), wherein the lap feeder (12, 12A, 26, 27) has a motor (26) that can be driven
independently of a combing drive device (24, 25), the lap feed control device (28)
being characterized in that
the lap feed control device (28) includes an arithmetic-logic unit (31) and a control
unit (31), wherein when the comber is operated with the motor (26) driven at a constant
speed on a trial basis, variation of weight of the sliver relative to decrease of
diameter of the lap roll (L) is measured, wherein the arithmetic-logic unit (31) calculates
a speed change pattern of the motor (26) from the measurements of the variation of
the weight of the sliver to equalize the weight of the sliver or reduce the variation
of the weight of the sliver, wherein the control unit (31) controls operation of the
motor (26) of the lap feeder (12, 12A, 26, 27) in accordance with the speed change
pattern.
2. The lap feed control device according to claim 1, characterized in that the arithmetic-logic unit (31) regards a speed change ratio as K / {(the weight of
the sliver determined at the diameter of the lap roll (L) when speed is changed) /(the
weight of the sliver at a reference diameter of the lap roll (L))} in calculating
the speed change pattern, wherein K is a proportional constant.
3. The lap feed control device according to claim 2, characterized in that the proportional constant K is set at a value that is previously calculated for material
of the lap.
4. The lap feed control device according to claim 2 or 3, characterized in that the speed change pattern has a plurality of transition points and a plurality of
sections divided by the transition points, wherein the speed change ratio is set at
each transition point, wherein the speed change ratio between two of the adjacent
transition points is set in accordance with the speed change ratios of the two adjacent
transition points.
5. The lap feed control device according to any one of claims 1 through 4, characterized in that the arithmetic-logic unit (31) has a filter for the measurements, wherein the filter
is operable to block the variation of the weight of the sliver in a range that is
less than unit length of the sliver.
6. The lap feed control device according to any one of claims 1 through 5, characterized in that the speed change pattern is represented by a change of a speed change ratio or a
speed change factor relative to consumption lap length.
7. A lap feed control method for controlling feed of lap in a comber, wherein the comber
is operable to produce a sliver from the lap wound in the form of a lap roll (L) and
has a plurality of combing heads (11) each having a lap feeder (12, 12A, 26, 27),
wherein the lap feeder (12, 12A, 26, 27) has a motor (26) that can be driven independently
of a combing drive device (24, 25), the lap feed control method being
characterized by:
a step of measuring weight of the sliver for each predetermined length while operating
the comber with the motor (26) driven at a constant speed on a trial basis;
a step of calculating a speed change pattern of the motor (26) from the measurements
of the weight of the sliver in view of change of diameter of the lap roll (L) to equalize
the weight of the sliver or reduce variation of the weight of the sliver; and
a step of controlling operation of the motor (26) of the lap feeder (12, 12A, 26,
27) in accordance with the speed change pattern.
8. The lap feed control method according to claim 7, characterized in that the speed change pattern is represented by a change of a speed change ratio or a
speed change factor relative to consumption lap length.