U.S. patent application number 12/595972 was filed with the patent office on 2010-05-06 for web conveyance controlling method, web slip amount measuring means, and web conveyance controlling device.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Toshio Fuwa.
Application Number | 20100108733 12/595972 |
Document ID | / |
Family ID | 39943373 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108733 |
Kind Code |
A1 |
Fuwa; Toshio |
May 6, 2010 |
WEB CONVEYANCE CONTROLLING METHOD, WEB SLIP AMOUNT MEASURING MEANS,
AND WEB CONVEYANCE CONTROLLING DEVICE
Abstract
A method of controlling the conveyance of a web comprises a web
measuring step of measuring the conveyance speed (V) and the
tension force (T) of the web (2) during its conveyance, a slip
amount calculation step of calculating the slip amount (W) of the
web (2) relative to a guide roll (14) from the values of the
conveying speed (V) and the tension force (T) of the web (2)
measured in the web measuring step, and a web control step of
controlling the tension force of the web (2) during its conveyance
so that the slip amount (W) of the web (2) relative to the guide
roll (14) calculated in the slip amount calculation step is equal
to a preset target slip amount (W1). Consequently, the slip of the
web is accurately controlled, whereby the lateral displacement of
the web can be reduced.
Inventors: |
Fuwa; Toshio; (Nissin-shi
Aichi, JP) |
Correspondence
Address: |
GIFFORD, KRASS, SPRINKLE,ANDERSON & CITKOWSKI, P.C
PO BOX 7021
TROY
MI
48007-7021
US
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
39943373 |
Appl. No.: |
12/595972 |
Filed: |
April 7, 2008 |
PCT Filed: |
April 7, 2008 |
PCT NO: |
PCT/JP2008/057225 |
371 Date: |
October 15, 2009 |
Current U.S.
Class: |
226/1 ;
226/24 |
Current CPC
Class: |
B65H 2515/815 20130101;
B65H 2515/31 20130101; B65H 23/1888 20130101; B65H 2220/03
20130101; B65H 2220/02 20130101; B65H 2220/03 20130101; B65H
2515/815 20130101; B65H 2220/01 20130101; B65H 2220/03 20130101;
B65H 23/042 20130101; B65H 2515/31 20130101; B65H 2513/10 20130101;
B65H 2513/10 20130101; B65H 23/188 20130101 |
Class at
Publication: |
226/1 ;
226/24 |
International
Class: |
B65H 23/00 20060101
B65H023/00; B65H 20/02 20060101 B65H020/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2007 |
JP |
2007-119877 |
Claims
1. A web conveying control method of controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: a step of measuring a conveying
speed and tension of the web during conveying; a step of
calculating a slip amount of the web with respect to a guide roll
using the measured conveying speed and tension of the web; and a
step of controlling the conveying speed and/or the tension of the
web such that the slip amount becomes a target slip amount set in
advance.
2. The method according to claim 1, wherein the step of controlling
comprises: deciding whether a difference between the calculated
slip amount and the target slip amount is within a preset threshold
range; calculating, when deciding that the difference goes beyond
the threshold range, an ideal conveying speed or an ideal tension
of the web with regard to the target slip amount in case that the
conveying speed or tension is constant; and controlling the
conveying speed and/or the tension of the web so as to be the
calculated ideal conveying speed or ideal tension.
3. A web conveying control method of controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: a step of measuring a conveying
speed and tension of the web during conveying; a step of measuring
a rotational speed of a guide roll; a step of measuring the slip
amount of the web with respect to the guide roll on the basis of a
difference between the measured conveying speed of the web and the
measured rotational speed of the guide roll; and a step of
controlling the conveying speed and/or the tension of the web such
that the slip amount becomes a target slip amount set in
advance.
4. A web conveying control method of controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: a step of measuring a conveying
speed and tension of the web during conveying; a step of measuring
a rotational speed of a drive roll which conveys the web; a step of
measuring a rotational speed of a guide roll; a step of measuring
the slip amount of the web with respect to the guide roll on the
basis of a difference between the measured rotational speed of the
drive roll and the measured rotational speed of the guide roll; and
a step of controlling the conveying speed and/or the tension of the
web such that the slip amount becomes a target slip amount set in
advance.
5. A web conveying control method of controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: a step of measuring a conveying
speed and tension of the web during conveying; a step of detecting
a shifting amount of the web from a surface of the roll; a step of
measuring the slip amount of the web with respect to the roll on
the basis of the shifting amount; and a step of controlling the
conveying speed and/or the tension of the web such that the slip
amount becomes a target slip amount set in advance.
6. A web conveying control device for controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: means of measuring a conveying
speed and tension of the web during conveying; means of calculating
a slip amount of the web with respect to a guide roll using the
measured conveying speed and tension of the web; and means of
controlling the conveying speed and/or the tension of the web such
that the slip amount becomes a target slip amount set in
advance.
7. The device according to claim 1, wherein the means of
controlling comprises: means of deciding whether a difference
between the calculated slip amount and the target slip amount is
within a preset threshold range; and means of calculating, when
deciding that the difference goes beyond the threshold range, an
ideal conveying speed or an ideal tension of the web with regard to
the target slip amount in case that the conveying speed or tension
is constant, wherein the conveying speed and/or the tension of the
web is controlled so as to be the calculated ideal conveying speed
or ideal tension.
8. A web conveying control device for controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: means of measuring a conveying
speed and tension of the web during conveying; means of measuring a
rotational speed of a guide roll; means of measuring the slip
amount of the web with respect to the guide roll on the basis of a
difference between the measured conveying speed of the web and the
measured rotational speed of the guide roll; and means of
controlling the conveying speed and/or the tension of the web such
that the slip amount becomes a target slip amount set in
advance.
9. A web conveying control device for controlling a slip of the web
with respect to a roll arranged in a conveying line for conveying
the web continuously, comprising: means of measuring a conveying
speed and tension of the web during conveying; means of measuring a
rotational speed of a drive roll which conveys the web; means of
measuring a rotational speed of a guide roll; means of measuring
the slip amount of the web with respect to the guide roll on the
basis of a difference between the measured rotational speed of the
drive roll and the measured rotational speed of the guide roll; and
means of controlling the conveying speed and/or the tension of the
web such that the slip amount becomes a target slip amount set in
advance.
10. A web conveying control device for controlling a slip of the
web with respect to a roll arranged in a conveying line for
conveying the web continuously, comprising: means of measuring a
conveying speed and tension of the web during conveying; means of
detecting a shifting amount of the web from a surface of the roll;
means of measuring the slip amount of the web with respect to the
roll on the basis of the shifting amount; and means of controlling
the conveying speed and/or the tension of the web such that the
slip amount becomes a target slip amount set in advance.
Description
TECHNICAL FIELD
[0001] The present invention relates to a web conveying control
method, a web slip amount measuring means, and a web conveying
control device, more particularly to a technique of controlling the
slip of the web with respect to the roll arranged in the conveying
line for continuously conveying the web.
BACKGROUND ART
[0002] Conventional conveying line continuously conveys a long work
("web") such as electrode members used for secondary batteries and
the control method thereof is well known. In such conveying line,
various rolls disposed therein are adjusted for a feedback control
of the conveying speed and tension of the web ("control of the
conveying speed and tension of the web"), so the web is stably
conveyed.
[0003] In the conveying line, "Disturbance" such as misalignment of
the rolls in the line and failure to control the speed causes the
lateral shift of the web (in other words, the web slides to the
wide direction to the conveying line). Especially, in order to
reduce the product costs, high speed handling of the web is
required, however, when the conveying speed becomes higher, the web
is easy to slip with respect to the rolls.
[0004] In view of preventing the web slip with respect to the roll,
JP-2000-143053 A discloses the technique, as to the tension of the
web continuously conveyed, that the tension of the web from the
dancer roll disposed in the bridle section is adjusted to be the
tension where the tension cut ratio of the bridle roll in the
bridle section is the same on the basis of the tension of the web
in the adjacent sections.
[0005] As disclosed in JP-2000-143053 A, the conventional control
method is the method for preventing the slip of the web by means of
controlling the tension of the web, however, in the condition that
the "disturbance" changes the conveying speed, the slip of the web
is not able to be prevented accurately with the tension control.
Especially, the lateral shift of the web with regard to the roll is
susceptible to the conveying speed and tension of the web, so that
when the "disturbance" changes the conveying speed, the prevention
of the slip by means of the tension control fails to keep the
performance of controlling the lateral position of the web.
[0006] Generally, the conveying line has guide rolls for
controlling the lateral position of the web, and the guide rolls
control the lateral position of the web with high-accuracy, so
keeping the quality of the web during the conveyance. The guide
rolls are disposed at the midway of the line, adopted as the
center-pivot type or end-pivot type depending on the disposed
position, and the relative angles to the line are changeable
pivoting around the axis thereof. Using such the guide rolls, when
the serpentine web is conveyed to the guide rolls, the guide rolls
changes the relative angles to the line such that the lateral shift
caused by the "disturbance" is canceled and the error is
corrected.
[0007] Unfortunately, in the technique of using the guide rolls for
controlling the lateral position of the web, when the slip occurs,
the change of the relative angle of the guide roll does not prevent
the slip, so the control for the lateral position may fail.
Further, the conventional method of controlling the web-conveyance
fails to control the slip when the "disturbance" changes the
conveying speed, so that, in using the guide rolls for controlling
the lateral position of the web, there occurs buckles on the web
due to the high tension of the web, or there occurs slipping of the
web due to the low tension of the web.
[0008] The present invention aims to provide a web conveying
control method, a web slip amount measuring means, and a web
conveying control device, in which the slip of the web is
accurately controlled, thereby reducing the lateral shift of the
web.
DISCLOSURE OF INVENTION
[0009] The problems to be solved by the present invention is
described above, the means of solving the problems will be
followed.
[0010] The first aspect of the present invention is a web conveying
control method of controlling a slip of the web with respect to a
roll arranged in a conveying line for conveying the web
continuously. The method includes: a step of measuring a conveying
speed and tension of the web during conveying; a step of
calculating a slip amount of the web with respect to the roll using
the measured conveying speed and tension of the web; and a step of
controlling the conveying speed and/or the tension of the web such
that the slip amount becomes a target slip amount set in
advance.
[0011] Preferably, the step of controlling includes: deciding
whether a difference between the calculated slip amount and the
target slip amount is within a preset threshold range; calculating,
when deciding that the difference goes beyond the threshold range,
an ideal conveying speed or an ideal tension of the web with regard
to the target slip amount in case that the conveying speed or
tension is constant; and controlling the conveying speed and/or the
tension of the web so as to be the calculated ideal conveying speed
or ideal tension.
[0012] The second aspect of the present invention is a web slip
amount measuring method, which includes: a step of measuring a
rotational speed of a guide roll; and a step of measuring the slip
amount of the web with respect to the guide roll on the basis of a
difference between the measured conveying speed of the web and the
measured rotational speed of the guide roll.
[0013] The alternative embodiment of the second aspect is a web
slip amount measuring method, which includes: a step of measuring a
rotational speed of a drive roll which conveys the web; a step of
measuring a rotational speed of a guide roll; and a step of
measuring the slip amount of the web with respect to the guide roll
on the basis of a difference between the measured rotational speed
of the drive roll and the measured rotational speed of the guide
roll.
[0014] The other embodiment of the second aspect is a web slip
amount measuring method, which includes: a step of detecting a
shifting amount of the web from a surface of the roll; and a step
of measuring the slip amount of the web with respect to the roll on
the basis of the shifting amount.
[0015] The third aspect of the present invention is a web conveying
control device for controlling a slip of the web with respect to a
roll arranged in a conveying line for conveying the web
continuously. The device includes: means of measuring a conveying
speed and tension of the web during conveying; means of calculating
a slip amount of the web with respect to the roll using the
measured conveying speed and tension of the web; and means of
controlling the conveying speed and/or the tension of the web such
that the slip amount becomes a target slip amount set in
advance.
[0016] Preferably, the means of controlling includes: means of
deciding whether a difference between the calculated slip amount
and the target slip amount is within a preset threshold range; and
means of calculating, when deciding that the difference goes beyond
the threshold range, an ideal conveying speed or an ideal tension
of the web with regard to the target slip amount in case that the
conveying speed or tension is constant, wherein the conveying speed
and/or the tension of the web is controlled so as to be the
calculated ideal conveying speed or ideal tension.
[0017] The advantageous embodiment of the third aspect includes:
means of measuring a rotational speed of a guide roll; and means of
measuring the slip amount of the web with respect to the guide roll
on the basis of a difference between the measured conveying speed
of the web and the measured rotational speed of the guide roll.
[0018] The alternative embodiment of the third aspect includes:
means of measuring a rotational speed of a drive roll which conveys
the web; means of measuring a rotational speed of a guide roll; and
means of measuring the slip amount of the web with respect to the
guide roll on the basis of a difference between the measured
rotational speed of the drive roll and the measured rotational
speed of the guide roll.
[0019] The other embodiment of the third aspect includes: means of
detecting a shifting amount of the web from a surface of the roll;
and means of measuring the slip amount of the web with respect to
the roll on the basis of the shifting amount.
[0020] According to the present invention, in controlling the
web-conveyance, the slip of the web is accurately controlled,
thereby lowering the lateral shift of the web. In other words, in
conveying control for the web, if the "disturbance" changes the
conveying speed and tension of the web, the slip of the web is
controlled with high accuracy; as a result, the shift (lateral
shift) of the web with respect to the roll can be lowered.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a side view illustrating a conveying line provided
with a conveying control device as a first embodiment of the
present invention.
[0022] FIG. 2 is a block diagram showing the conveying control
device.
[0023] FIG. 3 is a map drawing a correlation table (tension versus
conveying speed).
[0024] FIG. 4 is a flowchart showing a conveying control method of
the conveying control device.
[0025] FIG. 5 is a side view illustrating a conveying line provided
with a conveying control device as a second embodiment of the
present invention.
[0026] FIG. 6 is a side view illustrating a conveying line provided
with a conveying control device as a third embodiment of the
present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] First of all, the whole structure of a conveying line 1 for
a web 2 will be described below.
[0028] As shown in FIG. 1, the line 1 contains a start roll 10
arranged at the upstream side and a feed roll 11 arranged at the
downstream side, and from the roll 10 to the roll 11, there are
guide rolls 12, 13, 14, 15, and a dancer roll 16 arranged in turn.
The web 2 is conveyed with being strained at these guide rolls at
certain angles.
[0029] The rolls 10, 11 have nip rolls 17, 18 disposed thereon,
respectively. The rolls 17, 18 are contacted and pressed to the
rolls 10, 11 by air-cylinders (not shown) or the like, for
preventing slips of the web 2 on the rolls 10, 11. The web 2 is fed
synchronously with the rolls 10, 11.
[0030] The start roll 10 is connected to a motor 10a, and the motor
10a is connected to a control unit 30. The feed roll 11 is
connected to a motor 11a, which is connected to the control unit
30.
[0031] Each of the bodies of the guide rolls 12, 13, 14, 15 is
pivoted on a rotation axis, thereby rotating in cooperated with the
web 2 conveyed along the line 1. The roll 14 of these guide rolls
12 to 15 is disposed at the middle of the line 1, in which a
relative angle of a pivot axis (not shown) to the line 1 can change
("end-pivot type"). According to this roll 14, when the web 2 is
conveyed serpentinely to the roll 14, the relative angle is changed
so as to counteract the lateral shift of the web 2, thereby
controlling the lateral position of the web 2 and correcting the
error.
[0032] The dancer roll 16 is disposed between a pair of fixed roll
19, 19 and pivots on one end of an arm 16a, which is swingably
supported on a support point 16b by the other end thereof. The arm
16a is connected to a motor 16c, and the motor 16c is connected to
the control unit 30 for swing-control.
[0033] In the conveying line 1, the web 2 is conveyed through the
start roll 10 pressed by the nip roll 17, the guide rolls 12 to 15,
the fixed roll 19, the dancer roll 16, the fixed roll 19, and the
feed roll 11 pressed by the nip roll 18 in sequence.
[0034] Next, a conveying control device 3 for the web 2 is
described below as a first embodiment.
[0035] The control device 3 aims to stably convey the web 2 along
the line 1, controls the conveying speed of the web 2 by adjusting
the drive of rolls 10, 11 and controls the tension of the web 2
with respect to the dancer roller 16 by swinging the arm 16a.
Specifically, the control method of the control device 3 is based
on the slip amount of the web 2 to the guide roll 14 in the line 1,
the conveying speed and tension are controlled to adjust the slip
of the web 2 with respect to the roll 14 and to reduce the shift
amount in the lateral direction.
[0036] As shown in FIG. 1, the control device 3 includes the
control unit 30 as a means for controlling the motor 10a and the
like to control the conveying speed and tension of the web 2, an
encoder 31 as a means for measuring the rotational speed of the
start roll 10, which conveys the web 2, a speedometer 32 as a means
for measuring the conveying speed of the web 2, a tension meter 33
for measuring the tension of the web 2, an encoder 34 as a means
for measuring the rotational speed of the guide roll 14, and a
guide controller 36 for controlling the relative angle of the roll
14 to the line 1. The encoder 31, speedometer 32, tension meter 33,
encoder 34 and controller 36 are both connected to the control unit
30.
[0037] The control unit 30 receives the signals from the encoder 31
and the like, and is composed of a CPU for processing, a memory for
storing the processing program, an interface for input the
operations for the CPU, a display such as CRT or LCD.
[0038] As shown in FIG. 2, the control unit 30 includes a conveying
speed control unit 30a for controlling the conveying speed of the
web 2, a tension control unit 30b for controlling the tension of
the web 2, a slip amount measuring unit 30c as a means for
measuring the slip amount of the web 2, a slip amount calculating
unit 30d as a means for calculating the real slip amount of the web
using the conveying speed and tension of the web 2, a deciding unit
30e as a means for deciding whether the difference is within the
preset threshold range between the real slip amount of the web 2
calculated by the unit 30d and the target slip amount set in
advance, and a calculating unit 30f as a means for calculating the
ideal tension of the web 2 to the target slip amount in the case
that the conveying speed of the web 2 is constant.
[0039] The conveying speed control unit 30a adjusts the motors 10a,
11a, connected to the control unit 30, to control the rotational
speed of the rolls 10, 11 to the target speed (target number of
revolution) set in advance. Especially, as to the start roll 10,
the encoder 31 is disposed at the drive shaft of the roll and
detects the rotational speed (number of revolution) of the roll 10.
The detected signal of the encoder 31 is transmitted to the unit
30, the unit 30a adjusts the motor 10a such that the roll 10
rotates at the target speed on the basis of the received signal. In
the embodiment, the unit 30a also adjusts the roll 11 to rotate
synchronously with the roll 10.
[0040] As described above, in the embodiment, the unit 30a adjusts
the rotations of the rolls 10, 11 to control the conveying speed of
the web 2 in the line 1.
[0041] The tension control unit 30b adjusts the motor 16c of the
arm 16a connected to the unit 30, to control the angle of the arm
16a to "the predetermined angle .theta.." "The predetermined angle
.theta." means the angle .theta. between the perpendicular from the
point 16b and the arm 16a, and is set in advance such that the
tension of the web 2 in the line 1 becomes the predetermined value
in response to the angle of the arm 16a (see FIG. 1).
[0042] In detail, an angle detection device (not shown) is provided
near the point 16b to detect the angle .theta. between the
perpendicular from the point 16b and the arm 16a, and the angle
detection device is connected to the unit 30 to transmit the detect
signal. The unit 30b adjusts the motor 16c to control the angle
.theta. of the arm 16a to the predetermined angle .theta. on the
basis of the received signal.
[0043] As described above, in the embodiment, the unit 30b changes
the swinging of the arm 16a to control the distance between the
fixed rolls 19 and the dancer roll 16, and the tension of the web 2
is set to the predetermined value (target tension).
[0044] The speedometer 32 (e.g. Doppler meter) measures the
conveying speed of the web 2 adjusted by the unit 30a as the real
speed. The tension meter 33 (e.g. tension sensor) measures the
tension of the web 2 adjusted by the unit 30b as the real
tension.
[0045] In detail, the speedometer 32, for example the laser Doppler
meter, is arranged near the guide roll 14, facing the surface of
the roll 14 through the web 2. The speedometer 32 is connected to
the unit 30 and transmits the detected signal to the unit 30. The
conveying speed of the web 2 measured by the speedometer 32
corresponds to the actual conveying speed (real speed) of the web 2
in the line 1.
[0046] The tension meter 33, for example the contact-type tension
sensor, is arranged near the guide roll 14, contacting the web 2 in
the line 1. The tension meter 33 is connected to the unit 30 and
transmits the detected signal to the unit 30. The tension of the
web 2 measured by the tension meter 33 corresponds to the actual
tension (real tension).
[0047] The slip amount measuring unit 30c measures the "slip amount
of the web 2," using the difference between the conveying speed of
the web 2 measured by the speedometer 32 and the rotational speed
of the guide roll 14 measured by the encoder 34 (see formula 1).
When the web 2 doesn't slip with regard to the roll 14, the
conveying speed of the web 2 should be equal to the rotational
speed of the roll 14. Actually, there exists air or the like
between the web 2 and the roll 14, so that the speeds of them are
not equal. So, in the embodiment, the difference between the
conveying speed of the web 2 and the rotational speed of the roll
14 is estimated to be the slip amount of the web 2.
SLIP AMOUNT=|CONVEYING SPEED OF WEB-ROTATIONAL SPEED OF GUIDE
ROLL|[Formula 1]
[0048] The encoder 34 is disposed at the drive shaft of the guide
roll 14, detects the rotational speed (number of revolution) of the
roll 14 and transmits the detected signal to the unit 30. The unit
30 measures the slip amount of the web 2 using the formula 1 on the
basis of the detected signals from the speedometer 32 and encoder
34.
[0049] As shown in FIG. 3, the unit 30c stores a correlation table
35 regarding the relationship between the slip amount W of the web
2 and the tension T of the web 2 in accordance with each of the
conveying speeds V (constant) of the web 2. The correlation table
35 shows that when the conveying speed V of the web 2 is constant
(for instance, see "v2" in FIG. 3), the slip amount W lowers in
response to the increase of the tension T of the web 2, and that
when the tension T of the web 2 is constant, the slip amount W
lowers in response to the increase of the conveying speed V
(v1<v2<v3). Note that the correlation table 35 is drawn
before conveying the web 2 in the line 1 and stored in the memory
(not shown) of the unit 30.
[0050] In the unit 30c, the correlation table 35 has a "target slip
amount (see "w1" in FIG. 3)" as a slip amount, in which there does
not occur the slip of the web 2 with respect to the guide roll 14.
Generally, the units 30a, 30b control the conveying speed (target
speed) and the tension (target tension) of the web 2 to match the
target slip amount set in the unit 30c.
[0051] The slip amount calculating unit 30d calculates the actual
slip amount (real slip amount) of the web 2 with respect to the
roll 14 in such a way that the real conveying speed and tension
measured by the speedometer 32 and tension meter 33 are substituted
for the correlation table 35 stored in the unit 30c.
[0052] The deciding unit 30e decides whether or not the difference
between the real slip amount of the web 2 calculated by the unit
30d and the target slip amount set by the unit 30c is within the
threshold range. The threshold range means the range where there
does not occur the slip of the web 2 with respect to the roll
14.
[0053] The calculating unit 30f calculates the ideal tension of the
web 2 in case that the conveying speed of the web 2 is constant
when the unit 30e decides the difference between the real slip
amount and the target slip amount goes beyond the threshold range.
Note that the unit 30e decides the difference between the real slip
amount and the target slip amount is within the threshold range,
the ideal tension of the web 2 is not calculated.
[0054] The guide controller 36 controls the drive of the motor (not
shown) of the guide roll 14, swings the roll around the pivot axis
and adjusts the relative angle of the roll to the line 1. In the
embodiment, the slip amount is adjusted by controlling the
conveying speed and tension of the web 2 and furthermore the
controller 36 changes the relative angle to the conveying line so
as to cancel the lateral shift of the web 2, thereby adjusting the
lateral position of the web 2.
[0055] Note that the guide controller 36 may be included in the
control unit 30 of the control device 3.
[0056] According to the above-described structure, in the conveying
control device 3, the target conveying speed and target tension of
the web 2 are replaced and given as feedback on the basis of the
results from the units 30e, 30f. When the unit 30e decides that the
difference between the real slip amount and the target slip amount
goes beyond the threshold range and the unit 30f calculates the
ideal tension, the ideal tension is set as the target tension and
the unit 30b control such that the tension of the web 2 becomes the
target tension. On the other hand, when the unit 30e decides that
the difference between the real slip amount and the target slip
amount is within the threshold range and the unit 30f does not
perform the calculation regarding the ideal tension, the setting of
the target tension is kept and the unit 30b continues to control
the tension of the web 2. Thus, the unit 30a continuously controls
the conveying speed of the web 2 to the target speed.
[0057] Then, the conveying control method for the web 2 is
described below.
[0058] As shown in FIGS. 3, 4, in the embodiment, the conveying
control device 3 is used for controlling the slip of the web 2 with
respect to the guide roll 14 in the line 1 and for conveying the
web 2 continuously, the method includes the following steps.
[0059] Before the conveying control of the web 2, the correlation
table 35 is drawn, in advance, representing the relationship
between the slip amount W of the web 2 and the tension T of the web
2 in accordance with each of the conveying speeds V (constant) of
the web 2. The correlation table 35 is stored in the memory (not
shown) of the control unit 30. In the following explanation of the
embodiment, the target speed is set constant (v2), and when the
target tension is (t1), the target slip amount is (w1).
[0060] When the conveying of the web 2 is actually controlled, the
real speed and real tension of the web 2 are measured during
conveying (S100). Here, in this explanation, the results of
measurement of the speedometer 32 and tension meter 33 are assumed
to be the real speed v3 (v3<v2) and the real tension t2
(t2<t1). Then, using the measured value (the real speed v3 and
the real tension t2), the real slip amount w2 of the web 2 is
picked on the basis of the correlation table 35 (S101).
[0061] In the next step, it is decided whether the difference
between the real slip amount w2 of the web 2 and the target slip
amount w1 is within the threshold range or not (S102). Deciding the
difference between the real slip amount w2 of the web 2 and the
target slip amount w1 goes beyond the threshold range, the ideal
tension t3 of the web 2 with respect to the target slip amount w1
when setting the real speed of the web 2 to constant (v3) is
calculated (S103).
[0062] The ideal tension (t3) calculated in the above step is set
as the target tension of the conveyed web 2 (S104), controlling
such that the tension of the conveyed web 2 becomes the ideal
tension t3 (S106). Note that, at the same time, the conveying speed
of the web 2 is adjusted to the target speed v2, and the web 2 is
consequently conveyed at the target speed v2 and target tension
t1.
[0063] On the other hand, decided whether the difference between
the real slip amount w2 of the web 2 and the target slip amount w1
is within the threshold range or not (S102), and the difference
between the real slip amount w2 of the web 2 and the target slip
amount w1 is decided to be within the threshold range and the and
the target tension is set to the target tension t1 (S105), and
controlling such that the tension of the web 2 becomes the target
tension t1 (S106).
[0064] The guide controller 36 controls the relative angle of the
guide roll 14 to the line 1, adjusting the lateral position of the
web 2 (S107).
[0065] As described above, the conveying control method for the web
2 of the embodiment includes a web measurement step of measuring
the conveying speed V and tension T of the web 2 in conveyed, a
slip amount calculation step of calculating the slip amount W of
the web 2 with respect to the guide roll 14 using the conveying
speed V and tension T of the web 2 measured by the web measurement
step, a web control step of controlling the tension of the web 2 in
conveyed such that the slip amount W of the web 2 calculated in the
slip amount calculation step becomes the target slip amount W1 set
in advance, so that the slip of the web 2 is accurately controlled
and the lateral shift of the web 2 is lowered.
[0066] More specifically, the control method of the embodiment is
to control the conveying speed and tension of the web 2 on the
basis of the slip amount of the web 2 with respect to the guide
roll 14, accordingly, when the "disturbance" occurs and the
conveying speed or tension of the web 2 change, the conveying speed
and tension of the web 2 are controlled by using the slip amount of
the web 2 with respect to the roll 14, so that the slip of the web
2 is accurately controlled. Furthermore, the slip of the web 2 is
controlled by above method; as a result, the shift (lateral shift)
of the web 2 with respect to the roll 14 is prevented. The
operation of the guide roll 14 makes the control for the lateral
position of the web 2 stable, which results in improvement in the
accuracy of the lateral position of the web 2.
[0067] Especially, in the embodiment, the web control step is the
step of deciding whether difference between the slip amount W
calculated in the slip amount calculation step and the preset
target slip amount W1 is within the threshold range or not, and
when decided the difference goes beyond the threshold range,
calculating the ideal tension of the web 2 with regard to the
target slip amount W1 in case that the conveying speed of the web 2
is constant and controlling the tension of the web 2 to meet the
calculated ideal tension, therefore, controlling the conveying
speed or tension makes it easy to control the web 2 without
slipping with respect to the guide roll 14.
[0068] Additionally, in the embodiment, as a slip amount
measurement step for the web 2, a step of measuring the rotational
speed of the guide roll 14 is included and the slip amount W of the
web 2 is measured on the basis of the difference between the
conveying speed of the web 2 and the rotational speed of the drive
shaft of the guide roll measured by the above-step. Such a
measurement method achieves the low relative-error between the
conveying speed of the web 2 and the rotational speed of the guide
roll 14, thereby enhancing the accuracy such as the control of the
slip of the web 2.
[0069] The structures of the conveying control method of the web 2
and the conveying control device 3 are not limited to the
above-described embodiment.
[0070] Note that in the following explanation, the same structures
as above-described embodiment are given the same numerals and
abridged.
[0071] The slip amount measuring method of the first embodiment
described before is based on the difference between the conveying
speed of the web 2 and the rotational speed of the guide roll 14
measured by the suitable method of measuring the rotational speed
of the guide roll, and in the second embodiment shown in FIG. 5,
the slip amount of the web 2 is measured on the basis of the
difference between the rotational speed of the start roll 10
measured by the encoder 31 and that of the guide roll 14 measured
by the encoder 34 as the measuring method (see formula 2).
SLIP AMOUNT=|ROTATIONAL SPEED OF START ROLL-ROTATIONAL SPEED OF
GUIDE ROLL| [Formula 2]
[0072] In this embodiment, the speedometer 32 may not be disposed
for measuring the real speed of the web 2 with respect to the guide
roll 14. In addition, the rolls of measurement objects may be
selected as the guide roll 14 and the guide roll 13 disposed near
the roll 14, without limiting the selection of the guide roll 14
and the start roll 10, and may be measured the difference of the
rotational speeds of them.
[0073] Moreover, as the slip amount measurement method for the web
2, the third embodiment shown in FIG. 6 provides a lifting amount
detect sensor 132 for detecting the lifting amount of the web 2
from the surface of the guide roll 14 and the method of measuring
the slip amount of the web 2 with regard to the guide roll 14 on
the basis of the lifting amount of the web 2 (see formula 3). The
lifting amount detect sensor 132 is, for example, composed of a
non-contact laser sensor, and detects the distance between the
surface of the roll and the web 2.
SLIP AMOUNT=|LIFTING AMOUNT OF WEB| [Formula 3]
[0074] The distance between the surface of the roll and the web 2
relates to the "slip" of the web 2 on the guide roll 14, and the
distance between the surface of the roll and the web 2 goes beyond
the given value, then the same phenomenon may occur as the slip of
the web 2 with respect to the guide roll 14. In the case, the
reason of changing the distance between the surface of the guide
roll 14 and the web 2 is thought to be an air-entry into the space
between the surface of the roll and the web 2 caused by quickening
the conveying speed of the web 2. Furthermore, as to the
embodiment, the encoder 34 may not be disposed for measuring the
rotational speed of the guide roll 14.
[0075] The conveying control device 3 stores the correlation table
35 showing the relationship between the slip amount W of the web 2
and the tension T of the web 2 in accordance with each of the
conveying speeds V (constant) of the web 2, however, the contents
or the drawing method of the correlation table 35 is not limited.
For example, the correlation table may show the relationship
between the between the slip amount W of the web 2 and the
conveying speed V of the web 2 in accordance with each of the
tensions T (constant) of the web 2. In this case, the conveying
control performs such that the tension of the web 2 becomes
constant, the conveying speed is likewise adjusted to the target
speed or ideal speed.
[0076] The structures of the rolls provided in the conveying line 1
may be nip rolls or bridle rolls. Further, the various measuring
instruments may be employed for the above-described structure. The
web 2 conveyed in the line 1 is not limited to the electrode member
(sheet) and may be a long work continuously conveyable.
INDUSTRIAL APPLICABILITY
[0077] The present invention is applicable to the conveying control
when continuously conveying the long work ("web"), such as
electrode member, using the rolls disposed in the conveying
line.
* * * * *