JPH1072791A - Tension controller for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tension controller for a motor capable of smoothly performing threading operations. SOLUTION: This tension controller for a motor is equipped with a cutter 4 for cutting a sheet of paper from the full width to a narrow one before entry into a calender roll 3 and a tension controlling circuit 17, containing a speed controlling circuit in a minor loop and capable of changing over the motor during the speed control to a tension standard corresponding to a prescribed tension standard. In this case, an automatic paper width correction apparatus 11 composed of a paper width detecting circuit 13 capable of detecting the present paper width, a paper width correction arithmetic circuit 14 capable of correcting the tension to the tension standard value corresponding to the paper width detected with the paper width detecting circuit 13 and a correction starting time arithmetic circuit 16 capable of delaying the correction starting time during a period from the narrow width at the time of threading to the time when the paper changed to the full width after the threading reaches the calender roll 3 is installed to thereby automatically correct the tension standard and control the tension so as to keep the tension constant even if the paper width is changed from the narrow one to the full one. As a result, operations of an operator can be reduced and the accurate tension control can readily be carried out to smoothly perform the threading operations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension control device for an electric motor for controlling the tension of paper in a paper machine for producing paper.

[0002]

2. Description of the Related Art In a paper machine for producing paper, each part after a final dryer part is operated so as to keep the tension of the paper between a roll at a preceding stage constant. In order to keep the paper tension constant, a tension detector is attached to the paper roll, its output is used as a feedback signal, and the deviation from a tension reference signal set in advance to a predetermined tension is calculated as P.
I control is performed, and the result is corrected as a tension correction signal to a speed reference of a motor control device including a speed control in a minor loop.

[0003] Normally, tension control is such that the paper is in the full width state,
After the paper tension is stabilized to some extent (when fluttering of the paper is eliminated), the tension control is performed. When the paper is passed, the tension control is turned off and only the speed control is performed.

[0004]

Recently, the papermaking technology has been improved in each step as compared with the conventional technology due to the improvement of the performance of the paper machine and the quality of the raw material, and the stability of the paper tension has been quickened. Taking advantage of the tension control from the time of threading, the threading operation after the dryer part has been performed with the tension of the paper kept constant.

However, since the setting device attached to the operation panel for setting the tension reference is controlled by the tension value in the entire width of the paper, it is controlled by the narrow width at the time of threading and the full width after the threading. It is necessary to adjust the setting device. If this is neglected, the tension becomes too high at the time of the narrow width, and the tension becomes loose at the time of the full width.

The present invention has been made in view of the above circumstances, and an object of the present invention is to automatically set a tension reference from a narrow width at the time of threading to a full width after the threading, thereby enabling an operator to operate the apparatus. An object of the present invention is to provide a tension control device for an electric motor capable of smoothing a paper threading operation by reducing the work and performing accurate tension control.

[0007]

In order to achieve the above object, a first aspect of the present invention is to provide a tension detector for detecting a tension of paper passing through a dryer roll and further passing through a calender roll, A cutter that cuts the paper from full width to narrow width before entering, and a tension control circuit that includes a speed control circuit in a minor loop and switches the motor under speed control to a tension reference corresponding to a predetermined tension reference. In the tension control device, a paper width detection circuit for detecting the current paper width, a paper width correction operation circuit for correcting the tension to a tension reference value corresponding to the paper width detected by the paper width detection circuit, and And a correction start time calculating circuit for delaying the correction start time until the paper having reached the full width of the paper reaches the calender roll. Accordingly, characterized by being configured to tension control so that the tension is corrected automatically tension reference even width changes from a narrow width when the paper through to full width after threading constant.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of one embodiment of the present invention.

As shown in FIG. 1, when the paper 1 coming out of the dryer roll 2 is passed through the calender roll 3, the cutter 4 is moved in the paper width direction to reduce the width from the full width to the narrow width through which the paper is passed. The paper is cut, passed through a paper roll on which a tension detector 6 is mounted, and sent to the calender roll 3. At this time, the tension of the paper is detected by the tension detector 6.

The calendar roll 3 has a speed reference circuit (D
RH) 7 outputs the speed reference signal to the drive device 8
And a speed detector (PG) attached to the motor 9
Drive is performed so that the speed is constant by the speed feedback signal of 10.

Until the narrow-width paper 1 to be threaded is fed to the calender roll 3, it is driven by the above speed control. When the paper is wound around the calender roll 3, the tension control input switch 18 is turned on, and the speed control is started. Switch to tension control.

On the other hand, in tension control, a tension setting device (TRH) 12 attached to an operation panel sets a predetermined tension value at the full width, and the tension reference signal is a paper width correction operation circuit 14 of the automatic paper width correction device 11. Is input to

The paper width correction operation circuit 14 responds to a tension reference signal at full width by a position detector 5 attached to the cutter 4.
The current paper width is calculated by the paper width detection circuit 13 based on the signal (1), and is converted into a tension reference value corresponding to the paper width.

The converted tension reference value at the time of the threading width is associated with the tension feedback signal of the tension detector 6, and
The deviation amount is input to a tension control circuit (TC) 17 to correct the tension of the drive device 8.

When the paper threading is completed and the cutter 4 is moved to make the paper full width, the output of the paper width correction arithmetic circuit 14 is set by the tension reference, that is, the tension setter 12 in the full width. Change toward the value.

At this time, since there is a distance between the mounting position of the cutter 4 and the calender roll 3, the correction start time is calculated by the time required for the paper having the full width to reach the calender roll 3. Calculate at 16 and delay the change of the tension reference until the full width paper reaches the calender roll 3.

When the paper threading is performed with a higher tension than the full width when the paper is threaded, the taper amount setting unit 15 provided in the paper width correction operation circuit 14 adjusts the paper threading so that the narrower width is stronger. The correction of the taper amount is also calculated so that the set value is obtained when the entire width is reached.

[0019]

As described above, according to the present invention, by adding an automatic paper width correction device to a tension control system of a motor in which a tension control circuit is provided in a conventional motor drive device, a narrow width at the time of paper threading can be reduced. By automatically setting the tension reference up to the entire width after the paper threading, the operation work of the operator can be reduced, and the paper threading operation can be performed smoothly by performing accurate tension control.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention.

[Explanation of symbols]

1 ... paper, 2 ... dryer roll, 3 ... calender roll,
4 ... Cutter, 5 ... Position detector, 6 ... Tension detector, 7 ...
Speed reference circuit, 8 ... motor drive device, 9 ... motor,
10 speed detector, 11 automatic paper width correction device, 12 tension setting device, 13 paper width detection circuit, 14 paper width correction calculation circuit, 15 taper amount setting device, 16 correction start time calculation circuit, 17 tension Control circuit, 18 ... Tension control input switch.

Claims (1)

[Claims] 1. A tension detector for detecting a tension of paper passing through a dryer roll and further passing through a calender roll, a cutter for cutting the paper from full width to narrow width before entering the calender roll, and a speed control circuit. A tension control circuit for switching the motor under speed control to a tension reference corresponding to a predetermined tension reference, wherein the tension control circuit includes a tension control circuit for detecting a current paper width; A paper width correction arithmetic circuit that corrects to a tension reference value corresponding to the paper width detected in step 2, and a time from when the paper, which has become narrower at the time of threading to the full width after the threading, reaches the calender roll, and a correction start time The automatic paper width correction device, which is composed of a correction start time calculation circuit that delays the A tension control device for an electric motor, wherein a tension reference is automatically corrected to control the tension so that the tension is constant.