JP3780062B2 - Tension control method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tension control method and apparatus for controlling a tension applied to a web unwound from a roll to a predetermined value.
[0002]
[Prior art]
For example, in a machine that pulls out and uses a web wound on a roll such as a rotary printing press, an automatic paper splicing device can be used to stop a roll that is currently being unwound without stopping the operation of the machine ( Hereinafter, when the old roll is approaching the end, the new roll (hereinafter referred to as the new roll) can be automatically connected to continue the operation.
[0003]
In order to supply the web to a rotary printing machine or the like, a flying type automatic paper splicing device is provided with two or three rolls on a turret arm so as to be pivotable, and the old roll at the unwinding position is unwound. When approaching, after turning the turret arm and moving the new roll to the splicing position, the new roll is pre-rotated by the pre-drive device, and the surface speed is the running speed (line speed) of the web being unwound After accelerating so that the speed is the same, the adhesive material adhered to the web tip of the new roll, for example, the old roll web is pressed against the double-sided tape by the adhesive roll and adhered, and the old part behind the bonded part The web drawn from the roll is cut by a cutter.
[0004]
Furthermore, in the automatic paper splicing device, the web is pulled out to prevent the web from being loosened and the web is broken due to excessive tension. The torque (braking force) of the brake device is appropriately adjusted so that the web tension is constant (Japanese Patent Laid-Open No. 7-41221).
[0005]
[Problems to be solved by the invention]
In a printing machine, when a paper jam occurs at a cutting / folding portion, the paper splicing device needs to be urgently stopped or decelerated rapidly.
For this reason, conventionally, an emergency stop or rapid deceleration command is output, and a braking force several times the usual is applied to a brake device provided coaxially with the roll.
[0006]
However, in such a method, an appropriate braking force cannot be obtained corresponding to the roll diameter or the line speed. Therefore, a method of adjusting the braking force in consideration of the roll diameter of the web (Japanese Patent Laid-Open No. 5-124178), Furthermore, a method for adjusting the braking force in consideration of the web roll diameter and the line speed (Japanese Patent Laid-Open No. 6-48630) has been developed.
However, even if the roll diameter and line speed are the same, if the web paper quality is different, the density will change, so the moment of inertia of the roll will be different, and if the braking force is uniformly set by the method described above, the appropriate braking force Was not obtained.
[0007]
For example, a paper with a density of 40 g / m ^{2 and} a paper with a density of 70 g / m ² have a weight difference of about 1.75 times, but the same braking force (control) is required during an emergency stop or sudden deceleration. When the power is applied, the paper having a density of 40 g / m ² has an excessive tension and may break the paper, as shown in FIG. 2A, and the paper having a density of 70 g / m ² As shown in FIG. 2B, there is a problem that the tension becomes too small and the web is loosened.
[0008]
For this reason, conventionally, whenever the paper quality differs, the braking force at the time of emergency stop or sudden deceleration must be readjusted, and even if readjusted, measurement work such as measuring the weight of the roll is required. Furthermore, there are complicated operations such as forgetting adjustment and setting errors.
The present invention has been made in view of the above prior art, and provides a tension control method and apparatus capable of applying an appropriate braking force during emergency stop or sudden deceleration of the web according to the density of the web. There is.
[0009]
[Means for Solving the Problems]
The tension control method according to claim 1 of the present invention for achieving such an object detects the tension applied to the web unwound from the roll, and applies a braking force to the roll to maintain the tension at a predetermined value. In the tension control method to be adjusted, acceleration torque when the roll is accelerated by the drive device is detected and stored in advance, and the roll diameter of the roll when accelerated is stored, and then an emergency stop or rapid deceleration signal is stored. The acceleration torque and the roll diameter when accelerating are read out, the roll diameter of the current roll is measured, the acceleration torque of the roll and the roll diameter when accelerating, and the measured current roll diameter The braking force for the roll is adjusted based on the above.
[0010]
The tension control device according to claim 2 of the present invention that achieves the above object detects the tension applied to the web unwound from the roll, and adjusts the roll by applying a braking force to maintain the tension at a predetermined value. A tension control device that brakes the roll, means for detecting acceleration torque when the roll is accelerated by a drive device, means for storing the acceleration torque, and a current roll diameter of the roll. Means for measuring, means for storing the roll diameter of the roll when accelerating, means for giving an emergency stop or sudden deceleration signal, and the acceleration torque and the acceleration when an emergency stop or sudden deceleration signal is given The roll diameter at the time is read out, and the braking force for the roll is obtained based on the acceleration torque, the roll diameter at the time of acceleration and the current roll diameter, and the block Characterized in that it comprises a means for outputting to a rk device.
The tension control method according to claim 3 of the present invention that achieves the above object detects the tension applied to the web unwound from the roll, and adjusts the roll by applying a braking force to maintain the tension at a predetermined value. In the tension control method, the pre-drive device detects and stores the acceleration torque when the surface speed of the roll is accelerated to the same speed as the running speed of the web being unwound at the time of paper splicing. The roll diameter of the roll when accelerating at the time of splicing is stored, and then the acceleration torque and the roll diameter when accelerating are read when an emergency stop or sudden deceleration signal is given, and the roll of the current roll The diameter is measured, and the braking force for the roll is adjusted based on the acceleration torque of the roll, the roll diameter when accelerated, and the measured current roll diameter. To.
The tension control device according to claim 4 of the present invention that achieves the above object detects the tension applied to the web unwound from the roll, and adjusts the roll by applying a braking force to maintain the tension at a predetermined value. And a braking device for braking the roll, and an acceleration torque when the surface speed of the roll is accelerated to the same speed as the running speed of the web being unwound by a pre-drive device during paper splicing Detecting means, means for storing the acceleration torque, means for measuring the current roll diameter of the roll, means for storing the roll diameter of the roll when accelerating during paper splicing, emergency stop or sudden A means for giving a deceleration signal; and when the emergency stop or sudden deceleration signal is given, the acceleration torque and the roll diameter at the time of acceleration are read and the acceleration torque and acceleration are read Characterized in that the roll diameter when the well based on the current roll diameter seeking braking force applied to the roll comprises a means for outputting to said braking device.
[0011]
[Action]
The present invention has been made paying attention to that the above problem can be solved by utilizing the fact that the acceleration torque when accelerating the roll by the drive device is increased or decreased in accordance with the moment of inertia of the roll.
That is, if the paper quality of the web is different, the weight of the roll formed by winding the web is different. Therefore, if the weight of the roll is measured, the moment of inertia can be calculated, but the weight of the roll should be measured one by one. Is complicated.
[0012]
Therefore, in the paper splicing device, when the old roll approaches the end, the new roll is accelerated by the drive device in advance, so that the acceleration torque is to be used.
Here, the relationship between the moment of inertia of the roll and the acceleration torque is expressed by the following equation.
T _AC = 2π (N ₁ −N ₀ ) (J _L + J _M ) / 60 · t _AC + T _L (1)
[0013]
However, T _AC is the acceleration torque (N / m),
T _L is the load torque (N / m),
N ₁ is the number of rotations after acceleration (r / min),
N ₀ is the rotation speed before acceleration (r / min),
t _AC is the acceleration time (s)
J _L is the moment of inertia of the roll (kg · m ² )
J _M is the moment of inertia (kg · m ² ) of the motor rotor.
[0014]
Here, assuming that the inertia moment J _M of the motor rotor is sufficiently smaller than the inertia moment J _{L of the} roll, it is assumed that J _L + J _M ≈J _L. The load torque _TL is a value converted to the motor shaft, but is ignored here as being sufficiently small compared to the first term on the right side of (1).
Therefore, equation (1) is approximated as:
[0015]
T _AC = 2πJ _L (N ₁ −N ₀ ) / 60 · t _AC (2)
On the other hand, the moment of inertia J _{L of the} roll is obtained by the following equation.
_{J L = (πρ / 32)} × (L / 10 3) {(D 2/10 3) 4 - (D 1/10 3) 4} ... (3)
Where ρ is density (kg / m ³ ),
L is the length of the roll (mm),
D ₂ is the outer diameter of the roll (mm),
D ₁ is the inner diameter (mm) of the roll.
[0016]
Here, the initial weight W of the roll is expressed by the following equation.
W = (ρπ / 4) ( L / 10 3) {(D 2/10 3) 2 - (D 1/10 3) 2} ... (4)
Substituting this equation (4) into equation (3) leads to the following equation:
_{J L = (W / 8)} {(D 2/10 3) 2 + (D 1/10 3) 2} ... (5)
[0017]
If the equations (2) and (5) are combined and solved for W, the following equation is derived.
_{W = 8 · 60 · T AC} · t AC / 2π (N 1 -N 0) {(D 2/10 3) 2 + (D 1/10 3) 2} ... (6)
Here, in the right side of the equation (6), the acceleration time t _AC and the inner and outer diameters D ₁ and D ₂ of the roll are known. Further, if the line speed is reached after roll acceleration, the rotation speed N ₁ after roll acceleration is also easily obtained. Further, the rotational speed N ₀ before acceleration can be set to zero.
[0018]
Therefore, as apparent from the equation (6), since it is recognized that the initial weight W of the roll and the acceleration torque T _AC are in a proportional relationship, the initial weight W of the roll can be calculated from the acceleration torque T _AC . Needless to perform such calculation, the braking force at the time of emergency stop and sudden deceleration may be determined according to the acceleration torque T _AC .
In other words, the greater the initial weight W of rolls, because acceleration torque T _AC is large, in order to stop this requires a large braking force, conversely, the smaller the initial weight W of rolls Since the acceleration torque T _AC is small, a small braking force is sufficient to stop the acceleration torque T _AC .
However, when an emergency stop or sudden deceleration signal is issued, the web has already been unwound from the roll and the roll diameter has become smaller, so the current roll diameter is measured, and the roll diameter is taken into account, Determine the braking force at emergency stop and deceleration.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 shows an embodiment of the present invention. The embodiment shown in the figure is an embodiment applied to a flying type automatic paper splicing device.
As shown in FIG. 1, the center of a turret arm 2 is rotatably mounted on the main body 1, and rolls 3 and 4 around which webs are wound are mounted on both ends of the turret arm 2.
[0020]
The state shown in FIG. 1 is a state in which the currently unrolled roll (old roll) 3 approaches the end, the turret arm 2 is turned, and the next new roll (new roll) 4 is moved to the paper splicing position. is there.
A brake device (not shown) is coaxially attached to each of the rolls 3 and 4, and its torque (braking force) is adjusted so that the tension of the drawn web is constant.
The roll diameter D of the old roll 3 is monitored by the remaining paper meter 5 and calculates how many minutes it will be necessary to continue withdrawing the web at the current web speed, so that there is a certain amount of time remaining. When it is time, the turret arm 2 turns and the new roll 4 moves to the splicing position.
[0021]
Further, the current winding diameter D of the old roll 3 measured by the remaining paper meter 5 is output to the sequencer 22.
In the turret arm 2, a pre-drive device (not shown) for rotating the rolls 3 and 4 is incorporated. By this pre-drive device, the surface speed of the new roll 4 moved to the paper splicing position becomes the web running speed. Until it reaches the same speed.
The pre-drive device is controlled as described above by giving a rotational speed command from the sequencer 22 to the pre-drive motor driver 40. The pre-drive motor driver 40 also determines the acceleration torque T _AC when the roll 4 is accelerated. A measuring device for measuring is incorporated, and the measured acceleration torque T _AC is output to the sequencer 22.
[0022]
A paper splicing device 6 is provided in the main body 1 so as to be movable in an oblique direction in the figure so as to approach the new roll 4 moved to the paper splicing position.
The paper splicing device 6 is provided with a fixed roll 7 and an adhesive roll 8 that can be protruded by an air cylinder 16, and a cutter 9 that can be protruded by an air cylinder (not shown).
Further, a tape position sensor 11 that detects the double-sided tape 10 at the web tip of the new roll 4 is provided in the vicinity of the adhesive roll 8.
The tape position sensor 11 outputs a tape position signal to the auto paster controller 19 at regular intervals each time the double-sided tape 10 is detected.
[0023]
On the other hand, the web drawn from the old web 3 passes through the gap between the new roll 4 and the splicing device 6, passes through a plurality of rolls 12, 13, 14, 15 and a major roll 17, and is printed by a rotary printing machine (not shown). Thereafter, the sheet is cut at a predetermined interval by the cutting device 18, and the cut web is further folded by a folding machine (not shown).
In this embodiment, a means for measuring the web tension is incorporated in the roll 13, and the web tension measured by the roll 13 is output to the tension control device 30.
The major roll 17 is provided with a major roll encoder 21, which outputs a pulse corresponding to the web traveling speed to the auto paster controller 19.
[0024]
The cutting device 18 is provided with a cutting signal sensor 20, which outputs a cutting signal to the auto paster controller 19 at predetermined intervals for cutting the web.
The cutting signal sensor 20 mechanically moves the cutting signal sensor 20 so that the web portion at the position of the tape position sensor 11 of the paper splicing device 6 when the signal is generated is cut by the cutting device 18. The cutting signal generation phase with respect to the rotation reference of the entire apparatus is adjusted by adjusting the number of pulses of the major roll encoder 21.
[0025]
Further, a sequencer 22 is provided for outputting a paper splicing signal to the auto paster controller 19 when the remaining paper amount of the old roll 3 detected by the remaining paper meter 5 becomes below a certain level.
Further, the sequencer 22 stores the acceleration torque T _AC at the time of acceleration output from the pre-drive motor driver 40 and obtains the initial weight W of the old roll 3 according to the above equation (6) based on the acceleration torque T _AC . The roll initial weight W is output to the tension control device 30 and the current winding diameter D of the old roll 3 measured by the remaining paper meter 5 is output to the tension control device 30.
[0026]
The initial weight W of the old roll 3 is the weight before the web is unwound.
Further, as described above, according to the equation (6), the roll initial weight W and the acceleration torque T _AC are proportional, and therefore the acceleration torque T _AC may be output instead of the roll initial weight W.
[0027]
Furthermore, based on the tape position signal from the tape position sensor 11, the cutting signal from the cutting device 18, the paper splicing signal from the sequencer 22, etc., until a certain condition that can avoid cutting of the connecting portion of the web is satisfied, An auto paster controller 19 that defers the operation timing of the adhesive roll 18 and the cutter 19 is provided. The auto paster controller 19 includes a CPU 19a, an adhesive roll counter 19b, and a cutter counter 19c.
[0028]
In addition, a tension control device 30 that outputs a brake command value to the brake device is provided so as to maintain the web tension measured by the roll 13 with respect to the tension reference value set by the sequencer 22.
That is, the tension control device 30 cancels the web tension measured by the roll 13 in accordance with the decrease / increase, and sets a brake command value so that the web tension is always maintained at a constant tension reference value. Sends to brake device and performs closed loop control.
[0029]
Further, when an emergency stop or rapid deceleration command is given, the tension control device 30 obtains a braking force larger than that in the normal time based on the initial roll weight W and the current winding diameter D output from the sequencer 22; The braking force is output to the brake device.
That is, as the initial weight W of the old roll 3 obtained by the sequencer 22 is larger, a larger braking force is required. Therefore, the braking force is increased in proportion to the initial roll weight W.
[0030]
For example, as shown in FIGS. 3 (a) and 3 (b), the initial roll weight W and the web density are proportional, so the braking force when the density is 40 g / m ² is B and the density is 70 g / m ^2. If the braking force for C is C, then the tension is kept constant as B <C.
In addition, since the web is already drawn out and the winding diameter D of the old roll 3 has decreased, a smaller braking force is sufficient as the winding diameter D is smaller.
Further, as shown in the equation (3), the moment of inertia is proportional to the winding diameter D4, so that the braking force is proportional to the winding diameter D to the fourth power.
In other words, a general technique is to obtain the braking force by multiplying the roll initial weight W and the fourth power of the winding diameter D by a proportional constant. Further, at the time of emergency stop, a larger value is set as the proportional constant than at the time of sudden deceleration. Choose.
[0031]
As described above, in this embodiment, if the paper quality of the web is different, the roll initial weight W is different, and the acceleration torque T _AC when accelerating in advance by the pre-drive device is increased or decreased. The torque T _AC is stored in advance, the roll initial weight W is obtained, and when an emergency stop or rapid deceleration command is given, the braking force is adjusted according to the roll initial weight W. As shown in FIGS. 3A and 3B, it is possible to always maintain a constant tension.
[0032]
Further, it is not necessary to readjust the braking force every time the paper quality of the web is different, and the labor of measuring the roll initial weight W can be saved.
In the above embodiment, the pre-drive motor driver 40 detects the acceleration torque. However, the present invention is not limited to this, and a torque detector may be provided separately.
Further, the acceleration torque can be detected from the power value supplied to the pre-drive motor.
Further, although the weight calculation is performed by the sequencer 22, it may be performed by the tension control device 30.
Furthermore, the brake device is not particularly limited, and powder, air, a motor type, etc. are used, and an ultrasonic type, a photoelectric type, etc. are used as the remaining paper meter.
In this embodiment, the method for measuring the acceleration torque at the time of pre-driving is described. However, immediately after the roll is mounted on the turret arm, the acceleration torque is measured by driving the pre-drive device. good.
[0033]
【The invention's effect】
As described above in detail based on the embodiments, in the present invention, since the acceleration torque for accelerating the roll is obtained in advance, according to the paper quality without separately measuring the weight of the roll. It is possible to obtain an appropriate braking force at the time of sudden deceleration or emergency stop and maintain the tension constant. It is not necessary to readjust the braking force every time the paper quality of the web is different, and the labor of measuring the initial roll weight can be saved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a tension control device according to an embodiment of the present invention.
FIG. 2 is a graph showing the relationship between a constant braking force and the resulting tension.
FIG. 3 is a graph showing the relationship between the braking force according to the paper quality and the resulting tension.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Turret arm 3 Old roll 4 New roll 5 Remaining paper total 6 Paper splicing device 7 Fixed roll 8 Adhesive roll 9 Cutter 10 Double-sided tape 11 Tape position sensor 12, 13, 14, 15 Roll 16 Air cylinder 17 Measure roll 18 Cutting Device 19 Auto Paster Controller 19a CPU
19b Adhesive roll counter 19c Cutter counter 20 Cutting signal sensor 21 Measure roll encoder 22 Sequencer 30 Tension control device 40 Pre-drive motor driver

Claims (4)

  In a tension control method in which a tension applied to a web unwound from a roll is detected and a braking force is applied to the roll to maintain the tension at a predetermined value, the roll is accelerated by a drive device in advance. Detect and store acceleration torque, store the roll diameter of the roll when accelerating, and then read out the acceleration torque and roll diameter when accelerated when an emergency stop or sudden deceleration signal is given A tension control method comprising: measuring a current roll diameter of the roll, and adjusting a braking force for the roll based on an acceleration torque of the roll, a roll diameter when the roll is accelerated, and a measured current roll diameter .   In a tension control device that detects the tension applied to the web unwound from the roll and maintains the tension at a predetermined value by applying a braking force to the roll, a brake device that brakes the roll, and a drive device Means for detecting acceleration torque when the roll is accelerated, means for storing the acceleration torque, means for measuring the current roll diameter of the roll, and means for storing the roll diameter of the roll when accelerated And means for giving an emergency stop or sudden deceleration signal, reading out the acceleration torque and the roll diameter when accelerated when the emergency stop or sudden deceleration signal is given, and the acceleration torque and roll diameter when accelerated, and Means for determining a braking force on the roll based on a current roll diameter and outputting the braking force to the brake device. Apparatus. In a tension control method for detecting tension applied to a web unwound from a roll and adjusting the roll by applying a braking force so as to maintain the tension at a predetermined value, a surface speed of the roll is detected by a pre-drive device during paper splicing. Detecting and storing the acceleration torque when accelerating until it reaches the same speed as the web traveling speed during unwinding, storing the roll diameter of the roll when accelerating at the time of paper joining, Reads the acceleration torque and roll diameter when accelerating when an emergency stop or rapid deceleration signal is given, measures the roll diameter of the current roll, accelerates the roll acceleration torque and roll diameter when accelerated, and A tension control method comprising adjusting a braking force applied to the roll based on a measured current roll diameter. In a tension control device that detects the tension applied to the web unwound from the roll and maintains the tension at a predetermined value by applying a braking force to the roll, a brake device that brakes the roll, and at the time of paper splicing Means for detecting acceleration torque when the surface speed of the roll is accelerated to the same speed as the running speed of the web being unwound by a pre-drive device; means for storing the acceleration torque; Means for measuring the roll diameter of the roll, means for storing the roll diameter of the roll when accelerating during paper splicing, means for giving an emergency stop or sudden deceleration signal, and when an emergency stop or sudden deceleration signal is given The acceleration torque and the roll diameter at the time of acceleration are read out, and the low torque is calculated based on the acceleration torque, the roll diameter at the time of acceleration and the current roll diameter. Tension control device characterized by comprising a means for outputting seeking braking force to the brake device for.

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