JPS6114055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling winder tension in a winder for winding hot strip on a mandrel.

Figure 1 shows the positional relationship of the pinch rolls and mandrel in a hot strip mill, where 1 is the rolling mill, 2 is the hot run table, 3 is the upper pinch roll, 4 is the lower pinch roll, 5 is the strip,
6 is a mandrel. The strip 5 rolled by the rolling mill 1 is wound onto a mandrel 6 via a hot run table 2 and pinch rolls 3 and 4.

During rolling, the rolling mill 1, pinch rolls 3 and 4,
Tension control is performed between the mandrel 6 and the mandrel 6.
In addition, after the strip 5 passes through the rolling mill 1, a constant tension is applied between the pinch rolls 3, 4 and the mandrel 6 to ensure good winding until the winding is completed. , tension control is performed.

Conventionally, when controlling tension, mandrel 6
By controlling the current of the DC machine of the rolling mill 1 or the speed of the DC machine of the pinch rolls 3 and 4,
The tension between them was kept constant. The winding speed of the strip 5 is determined by the rolling mill 1 or the pinch rolls 3 and 4, and the tension between the rolling mill 1 or the pinch rolls 3 and 4 and the mandrel 6 is controlled by controlling the current of the mandrel driving DC machine. It was controlled.

FIG. 2 shows a conventional tension control device, in which 14 is a DC machine for driving the upper and lower pinch rolls, and the upper and lower pinch rolls are mechanically connected. 15 is a tachometer generator mechanically coupled to the DC machine 14, and 8 is a speed control amplifier that inputs the deviation between the speed reference signal and the speed feedback signal and outputs a current reference signal. 12 is a current detector that detects the armature current and outputs a current feedback signal; 9 is a current control amplifier that inputs the deviation between the current reference signal and the current feedback signal and outputs a current deviation signal; 10 is the current deviation signal This is a phase controller that outputs gate control pulses based on.

Reference numeral 11 denotes an anti-parallel thyristor power supply that controls the speed of the DC machine 14 by changing its output voltage using the gate control pulse. 25 is a DC machine for driving the mandrel, 26 is a tachometer generator mechanically coupled to this DC machine 25, and 18 is a speed generator that inputs the deviation between the speed reference signal and the speed feedback signal and outputs a current reference signal. It is a control amplifier.

Further, 23 is a current detector that detects the armature current and outputs a current feedback signal, 20 is a current control amplifier that inputs the deviation between the current reference signal and the current feedback signal, and outputs a current deviation signal, and 21 is the current control amplifier that outputs the current deviation signal. The phase controller 22 outputs a gate control pulse based on the current deviation signal, and is an anti-parallel thyristor power supply that drives the DC machine by changing the output voltage according to the gate control pulse. 34 is a field control circuit which inputs a signal proportional to the diameter of the coil being wound on the mandrel and makes the field flux of the DC machine 25 proportional to the coil diameter, and 33 is a field winding.

In such a configuration, the mandrel 6 in FIG.
A constant tension control is performed between the rolling mill 1 and the pinch rolls 3 and 4. Accordingly, at the start of strip winding, the mandrel switches from speed control to current control. That is, before the strip 5 is wound around the mandrel 6, the speed of the mandrel is controlled so that the circumferential speed of the mandrel is slightly higher than the rolling speed of the strip 5 in order to prevent the strip from sagging when it is wound around the mandrel. Let's do it. From the beginning of winding to the end of winding, current control is performed to keep the tension constant.

The tension is controlled to be constant by making the coil diameter D proportional to the field flux Φ, making the tension F proportional to the armature current I, and controlling the current. That is, the motor torque T is as follows when K ₁ is a proportional constant: T=K ₁ ΦI ...(1), and the relationship between tension F and motor torque T is F・D/2=T=K ₁ ΦI ...(2 ) becomes. Therefore, if the field flux Φ and the coil diameter D are made proportional, then if K ₂ is a proportionality constant, then F = K ₂ I ...(3), and if the armature current I is constant, the tension F is constant. becomes. Here, a signal in which the field flux Φ and the coil diameter D are made proportional is given as a field current reference signal to the field circuit 34 in FIG.

Next, referring to FIG. 2, switching from speed control to current control will be explained. That is, before the strip 5 is wound around the mandrel 6, the speed is controlled by the speed reference signal 16. At this time contact 1
7 and 19 are closed and 28 is open. When the strip 5 is wound around the mandrel, the contacts 17 and 19 are opened and the contact 28 is closed to switch to current control using the tension reference signal 27 as the current reference. While the strip is being rolled in the rolling mill, the force of the rolling mill is strong enough to prevent the strip from slipping in the rolling mill. After the strip leaves the rolling mill, tension is applied between the pinch rolls and the mandrel.

In this case, the tension on the mandrel is greater than the tension on the pinch rolls, and the strip may slip on the pinch rolls. This is partly due to the fact that the output of the DC machine for driving the pinch rolls is smaller than that for driving the mandrel, but unlike a rolling mill, the pinch rolls do not roll the strip. For this reason, the tension applied to the strip cannot be maintained only by the frictional force between the pinch roll and the strip. Once a slip occurs between the pinch rolls and the strip, the mandrel is accelerated, its speed increases, and the tension between the pinch rolls and the mandrel decreases, resulting in poor winding.

The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a winder tension control method that keeps the tension constant during winding and does not increase the slip speed.

The present invention will be described below based on an embodiment shown in the drawings. In FIG. 3, the same reference numerals as those in FIG. 2 are the same, so the explanation will be omitted.
29 is a contact point that opens and closes the speed reference signal 7. Also, 3
0 is a contact point that opens and closes the output of the speed control amplifier 8. 31 is a contact that opens and closes a newly provided tension reference signal 32 for the pinch roll, and the tension reference signal 32 calculates the tension required for the strip and changes it to the DC machine armature current value for driving the pinch roll. Assume that it has been converted.

First, until the strip is wrapped around the mandrel,
Contacts 29 and 30 are closed, contact 31 is open, and the speed of the pinch roll is controlled. Similarly, contacts 17,1
9 is closed and contact 28 is open to control the speed of the mandrel. At the same time as the strip is wound around the mandrel, contacts 17 and 19 are opened and contact 28 is closed, and the current is controlled by a current reference value based on the tension reference signal 27 of the mandrel 6 to apply a constant tension to the strip.

As rolling progresses and the rear end of the strip passes through the rolling mill, contacts 29 and 30 open and contact 31 closes, and the pinch rolls are current-controlled at a current reference value based on tension reference signal 32. On the other hand, the speed of the mandrel is controlled by the speed reference signal 16 with contacts 17 and 19 closed and contact 28 opened.

Although the field of the pinch roll is not shown in the figure, it is controlled to maintain a constant field flux. In other words, if K ₃ is a proportional constant, the pinch roll tension F and the armature current I are as follows: F=K ₃ I (4), and the tension F is proportional to the armature current I. In addition, the mandrel speed standard 16 is based on the strip speed V, the coil diameter D, the mandrel speed N, and the proportionality constant K ₄ , so that the strip speed V is always constant N=K ₄ V/D ...... (5) , is calculated.

In this way, according to the present invention, by controlling the speed of the mandrel after the trailing end of the strip passes through the rolling mill, even if the strip slips on the pinch rolls after the trailing end of the strip passes through the rolling mill. , the strip speed is kept constant on the mandrel, so the strip speed does not increase. In addition, since the pinch roll is switched from speed control to current control to maintain constant tension between the pinch roll and mandrel, winding is performed as well as before.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a winder device, FIG. 2 is a block diagram of a conventional winder tension control device, and FIG. 3 is a block diagram of a winder tension control device according to an embodiment of the present invention. It is. 1...Rolling mill, 2...Hot run table, 3
...Upper pinch roll, 4...Lower pinch roll, 5
...Strip, 6...Mandrel, 7,16...
...Speed reference signal, 8,18...Speed control amplifier,
9, 20... Current control amplifier, 10, 21... Phase controller, 11, 22... Thyristor power supply, 2
7, 32...Tension reference signal.

Claims (1)

[Claims] 1 In a winding machine that winds the strip with a mandrel after passing through a rolling mill or pinch roll,
Before the trailing end of the strip passes through the rolling mill, the mandrel is controlled by current and the speed of the pinch rolls is controlled; after the trailing end of the strip passes through the rolling mill, the mandrel is controlled by speed and the pinch rolls are controlled by current to produce the strip. A winding machine tension control method characterized by keeping the tension applied to the winder constant.