JPH0451462B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tension control device for automatically controlling the tension of a sheet material such as paper being sent out from a reel or wound around a reel.

[Conventional technology]

FIG. 5 is an explanatory diagram showing a conventional tension control device. In the figure, 1 is a nip roll that determines the running speed of the sheet material 2, 3 is a motor that drives this nip roll, and 4 is a motor around which the sheet material 2 is wound. 5 is a powder brake that applies braking torque to the winding frame roll, and 51 is a coil that adjusts the brake torque of this powder brake. 6 is a tension detector that detects material 2 and tension;
7 is a tension setting device; 8 is a device for amplifying the difference between the setting value of this tension setting device 7 and the detection output of the tension detector 6;
This is a comparator that applies current to the coil 51 of the powder brake 5 according to this output value.

Next, the operation will be explained.

Sheet material 2 is drawn off by nip rolls 1. On the other hand, a current flows through the coil 51 of the powder brake 5 in the winding frame 4 and a brake torque is generated, so that a tension F is generated in the sheet material 2. This tension F is detected by the tension detector 6, and this detection output is output to the comparator 8. On the other hand, since the setting output of the tension setting device 7 is also input to the comparator 8, the difference between the two is amplified. In other words, if the tension of the sheet material 2 is smaller than the set tension, the detected tension F will be smaller than the tension set value _F0 ,
The output of the comparator 8 increases, causing a larger current to flow through the coil 51 of the powder brake 5 than before. Therefore, the brake torque T _B increases and the material 2
The tension F applied to the tension increases and finally becomes approximately equal to the tension setting value F ₀ determined by the tension setting device 7. In this way, the feeding tension of the sheet material 2 can be automatically controlled to a constant value based on the set value.

FIG. 6 shows an application to a winding tension control device, where 9 is a powder clutch that applies a driving torque to the winding frame 4, and 91 is a coil that adjusts the driving torque of this powder clutch 9. 10 is a reduction gear that determines the input rotational speed _Nio of this powder clutch. Note that the same components as those shown in FIG. 5 are given the same reference numerals.

Next, the operation of this winding tension control device will be explained. In this case as well, the tension F of the sheet material 2 is detected by the tension detector 4, as in the case of the feeding tension control shown in FIG.
Compare the setting value F ₀ . If the tension F is the set value
If F is smaller than ₀ , the output of comparator 8 increases;
A larger current will flow through the coil 91 of the powder clutch 9 than before. For this reason, the drive torque T _C increases, and the tension applied to the sheet material 2 increases, and finally becomes approximately equal to the tension value determined by the tension setting device 7.

[Problem that the invention seeks to solve]

The conventional tension control device is constructed as described above, so in the case of FIG. 5, the tension applied to the sheet material 2 is F, the diameter of the winding frame 4 is D, the rotation speed of the winding frame is N, and the brake If the torque is T _B and the line speed of the sheet material 2 is V, then the following electric power P will be consumed as heat by this powder brake 5.

P=ωT=2πN/60T _B =2π/60・V/πD・1/2DF =VF/60=V・9・8・F/600.164VF(W) ……(1) When this heat is large, the wind The disadvantage is that the temperature rise of the powder brake 5 must be suppressed by cooling or water cooling, and as a result, this energy must be discarded.

In addition, in the case of the tension control device shown in Fig. 6, if the input rotation speed of the powder clutch 9 is N _io , the output rotation speed is N _put , and the driving torque of the powder clutch 9 is T _C , the power consumed is P becomes as follows.

P=ωT=2πN/60T _C =2π/60T _C (N _io −N _put ) =π/30・T _C (N _io −N _put )(W) ……(2) N _put =V/πD・T _C = 1/2DF...(3) In equation (2), when the line speed V is constant, N _io is constant, and as the _winding progresses, D increases as shown in equation (3). Therefore, the term (N _io −N _put ) in equation (2) becomes
It gets bigger and bigger. On the other hand, the winding torque T _C is also (3)
As is clear from the formula, as D becomes larger, it becomes larger in direct proportion. As a result, the power P consumed by the powder clutch 9 increases rapidly in more than direct proportion as D increases. If this power consumption is large, it is necessary to suppress the temperature rise of the powder clutch 9 by wind cooling or water cooling, resulting in the disadvantage that this energy must be wasted.

In this case, as the diameter D increases and the output rotation speed N _put decreases, the reduction ratio of the reducer 10 is changed to the diameter D in order to reduce the input rotation speed N _io .
If the value of P in equation (2) is increased in accordance with
There was a problem that I had to set 0. It is also conceivable to use a DC motor for winding without using the powder clutch 9, but this poses problems such as the need to replace brushes and the like.

This invention was made to solve the above-mentioned problems, and by using an AC motor as a device for driving the winding frame, it is possible to regenerate the power consumed during feed-out control, and to improve the winding speed. The purpose of the tension control is to provide a tension control device that can control power consumption to be constant regardless of the diameter of the reel and is nearly maintenance-free.

[Means for solving problems]

The tension control device according to the present invention drives a winding frame on which sheet material is wound with an AC motor, detects the winding diameter of the sheet material on the winding frame with a winding diameter detector, and detects the winding diameter of the sheet material on the winding frame. Detecting the speed with a speed detector and detecting the tension of the sheet material with a tension detector, dividing the output of the speed detector by the output of the winding diameter detector in a divider,
This division result is corrected by a correction device. On the other hand, the output of the tension setting device and the reference tension setting device are compared by a comparator, and in the frequency voltage control device,
A reference frequency corresponding to the output of the correction device is generated, and a voltage of the reference frequency corresponding to the error output of the comparator is outputted, and these outputs are supplied to the windings of the motor to adjust the sheet material. The motor is configured to control the motor so as to maintain the tension at a certain level.

[Effect]

In the sheet material feeding device according to the present invention, the generated torque can be adjusted by applying a voltage with a frequency corresponding to the winding diameter to the AC motor and changing the applied voltage, so that the regenerative braking torque of the AC motor is used as the control torque. can be used, and this regenerated energy is returned to the power source. Therefore, we aim to save energy. In addition, in sheet material winding devices, the output rotation speed of the AC motor decreases as the winding diameter increases.
As a result, the sheet material is wound with constant power.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows an example of application to feed-out tension control.
Figure 2 shows an example of application to winding force control. In FIG. 1, 11 is an AC motor that applies a brake torque to the winding frame 4, and 61 is a coil that adjusts the rotation speed and brake torque of this AC motor. 12 is a winding diameter detector that measures the diameter D of the winding frame 4; 13 is a speed detector that detects the rotational speed of the nip roll 1 and the running speed V of the sheet material 2;
14 divides the output value V of the speed detector 13 by the output value D of the winding diameter detector 12, and calculates the rotation speed N of the winding frame 4.
A divider that obtains a value according to =V/πD, 15 is a certain amount of bias value −α at the output of the divider 14.
This is a correction device that adds 16 is the correction device 1
This is a variable frequency voltage generator having a frequency generator 62 that generates a reference oscillation frequency with the output of 5.
Reference numeral 63 is a voltage generating section in the variable frequency voltage generating device 16 that adjusts the output frequency voltage according to the output value of the comparator 8.

Next, the operation shown in FIG. 1 will be explained using FIGS. 3 and 4 showing motor torque characteristics. First, when the diameter D and line speed V of the winding frame 4 are detected from the winding diameter detector 12 and the line speed detector 13, the divider 14 calculates the rotation speed N of the winding frame 4 = (V/πD). do. Next, the correction device 15
The bias value -α is added to the reference frequency generator 6 of the variable frequency voltage generator 16.
2. Therefore, a voltage with a frequency corresponding to the synchronous rotation number N-α is applied to the winding 61 of the AC motor 11. On the other hand, since the winding frame 4 rotates at the rotation speed N as described above, the AC motor 11 also rotates at the same rotation speed. Therefore, the AC motor 11 is operated in a region where the regenerative control torque T _B is generated. When this control torque T _B is large, that is, when the motor torque characteristic is indicated by the dotted line a in Fig. 3, a large control torque is applied to the winding frame 4.
T _B is applied, and therefore a tension F greater than the tension set value F ₀ is also generated in the sheet material 2. Therefore, the detection output of the tension detector 6 becomes larger than the set output of the tension setting device 7, and the output of the comparator 8 decreases.This output is given to the voltage generation section 63 of the variable frequency voltage generation device 16, so that the output The voltage becomes "0" and the regeneration control torque T _B also becomes "0". Therefore,
Since the tension applied to the sheet material 2 suddenly becomes "0", the output of the comparator 8 increases again, and the tension value F due to the regenerative braking torque generated by the AC motor 11 becomes almost equal to the tension setting value _F0 . It will calm down somewhere. This state is indicated by the solid line b in FIG. Note that in the figure, the load T _l is generated by the tension F (T _l = 1/2FD).

Also, as the feeding progresses, the diameter D of the winding frame 4 increases.
gradually decreases and the rotational speed N becomes faster, but the divider 14 automatically calculates the rotational speed N, and the correction device 15 adjusts the synchronous speed of the AC motor 11 to a point that is α smaller than N. Therefore, the action of the automatic tension control described above and the action that the source of this tension is the regenerative braking torque of the AC motor 11 are performed in the entire range of the number of times of the winding frame 4.

Next, the winding tension control will be explained with reference to FIG. In the figure, 15 is a correction device that adds a certain amount of bias value +α to the output of the divider 14, and the same components as those shown in FIG. 1 are given the same numbers. The redundant explanation has been omitted.

Next, the operation of this embodiment will be explained using FIG. 4. The winding of the sheet material 2 is reversed in operation to that described with respect to FIG. Sawachi,
When the rotation speed N of the winding frame 4 is calculated by the divider 14, the correction device 15 generates an output obtained by adding +α to the above value. Since this output is given to the reference frequency generator 62 of the variable frequency voltage generator 16,
The winding 61 of the AC motor 11 has a synchronous speed N+α
A voltage with a frequency corresponding to is applied.

On the other hand, since the winding frame 4 rotates at the number of rotations N, the AC motor 11 also rotates at the same number of rotations. Therefore, the AC motor 11 is operated in a region where driving torque is generated. When this orbital torque is large, that is, when the motor torque characteristic is indicated by the dotted line a in FIG.
T _C is applied, and a tension F larger than the tension setting device F ₀ is generated in the sheet material 2. Therefore, the detector 6
The detected output becomes larger than the set value of the tension setting device 7, and the output of the comparator 8 decreases.This output is given to the voltage generator 63 of the variable frequency voltage generator 16, so the output voltage becomes "0". The driving torque
T _C also becomes “0”. Therefore, the tension F applied to the sheet material 2 also becomes "0" at the source, so the output of the comparator 8 increases again, and the tension value F due to the drive torque T _C generated by the AC motor 11 and the tension setting value
It will settle down when F ₀ becomes almost equal. This state is indicated by the solid line b in FIG.

Further, as winding progresses, the diameter D of the winding frame 4 increases and the rotational speed N becomes slower, but the divider 14 automatically calculates the rotational speed N, and the correction device 1
5, the synchronous speed of the AC motor 11 is set to α from N.
Therefore, the action of the automatic tension control described above is carried out over the entire rotational speed range of the winding frame 4. Furthermore, the output rotation speed of the AC motor 11 decreases as the winding diameter D increases, so the power consumption P at this time is P=ωT=2πN/60・T=π/30・V/πD・1/ 2DF = 1/60VF...(4). From this equation, the output can be kept constant regardless of the winding diameter D, resulting in energy savings compared to when a powder clutch is used. Furthermore, since a DC motor is not used, there is no need to replace brushes, etc.

In this embodiment, the diameter D of the winding frame 4 is directly measured by the winding diameter detector 12, but a rotation detector is provided on the winding frame 4, and this rotation speed and the nip roll 1 are measured directly. Of course, the rotation speed of the speed detector 13 may be calculated and the diameter D of the winding frame 4 may be calculated.

〔Effect of the invention〕

As described above, according to the present invention, the generated torque can be adjusted by applying to the AC motor a voltage with a frequency that corresponds to the winding diameter of the sheet material and a voltage that corresponds to the tension of the sheet during running. With this structure, the regenerative control torque of the AC motor can be used as the braking torque in the sheet material feed control, and this regenerative energy can be returned to the power source, which is a huge advantage from the standpoint of energy saving. Also, since it is an AC motor, there are no parts that wear out other than the pairing ring, which is an excellent advantage.

On the other hand, when applied to winding tension control, the motor output rotation speed decreases as the winding frame D becomes larger, so the power consumption trip is assumed to be constant regardless of the winding diameter, and compared to the conventional method using a powder clutch. This has an energy saving effect.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a tension control device according to one embodiment of the present invention, FIG. 2 is an explanatory diagram of another embodiment, and FIG. 3 is a torque diagram illustrating the operation of the tension control device of FIG. 4 is a torque-rotational speed characteristic diagram explaining the operation of the tension control device in FIG. 2, FIG. 5 is an explanatory diagram showing a conventional tension control device, and FIG. 6 is another conventional example. FIG. 2 is a sheet material, 4 is a winding frame, 6 is a tension detector,
7 is a tension setting device, 8 is a comparator, 11 is an AC motor, 12 is a winding diameter detector, 13 is a speed detector, 14
1 is a divider, 15 is a correction device, and 16 is a frequency voltage control device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. An AC motor that drives a reel around which sheet material is wound, a reel diameter detector that detects the reel diameter of the sheet material wound on the reel, and a reel diameter detector that detects the reel diameter of the sheet material wound on the reel. a speed detector that detects the running speed of the sheet material taken; a divider that divides the output of the speed detector by the output of the winding diameter detector; and a correction device that corrects the output of the divider. a tension detector that detects the tension of the sheet material; a comparator that compares the output of the tension detector with a reference tension output of the tension setting device to generate a comparison error output; and an output of the correction device. Accordingly, a reference frequency voltage is generated from the reference frequency generator, and
A tension control device comprising: a frequency voltage control device configured to output a voltage corresponding to the output of the comparator from a voltage generating section, and supply each voltage to a coil of the AC motor.