JPH0469006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tandem (continuous) rolling mill, and particularly relates to a tension control device for suppressing changes in thickness of rolled material at very low speeds and when stopped. It is something.

[Conventional technology]

A conventional device will be explained based on FIGS. 3 and 4 shown in JP-A No. 55-55204. In the figure, FIG. 3 is a so-called tandem rolling device in which a plurality of rolling rolls are arranged in series. 1 is the rolled material, 2 is the i-th rolling roll of the rolling mill, and 3 is the (i+
1) The rolling material 1 that has flown down the rolling roll 1 is delivered to the next rolling roll (not shown) via the rolling roll 3. Reference numeral 4 denotes a tension detector that detects the tension of the rolled material 1 located between the rolling rolls 2 and 3. When the tension detector 4 sends a detected value (T _FBK ) to the comparator 5, the comparator 5 detects the tension. The difference between the tension value (T _FBK ) and the target tension value (T _REF ) received from another source is determined, and this deviation is received by the proportional-integral calculation device 7, which calculates a tension correction value and sends it out as a correction signal. Reference numeral 8 denotes a speed adjusting device that adjusts the rotational speed of a motor 9 that drives the rolling roll 2 in accordance with the correction signal of the proportional-integral calculation device 7, and these devices 8 and 9 constitute a driving means for the rolling roll 2. There is.

When the tension detector 4 detects the tension in the rolled material 1 between the rolling rolls 2 and 3, it sends a detected value (T _FBK ) to the comparator 5. The comparator 5 calculates the deviation between this detected value (T _FBK ) and the target value (T _REF ) received from another source, and sends it to the proportional integral calculation device 7, where the tension correction value is calculated and a correction signal is generated. Then, the speed adjusting device 8 adjusts the rotational speed of the motor 9 and adjusts the rotation of the rolling roll 2 to obtain an appropriate tension.

[Problem that the invention seeks to solve]

However, in the conventional device, when the rotational speed of the rolling rolls 2 and 3 is above a predetermined value, the tension detector 4 operates effectively, but when the rotational speed of the rolling rolls 2 and 3 is below the predetermined value, (1) It is controlled by obtaining a correction signal each time, but when the value falls below a predetermined value, the responsiveness to this control deteriorates and it becomes impossible to sufficiently follow the high frequency fluctuations that indicate the detected tension. When the rolls 2 and 3 are rotated at a very low speed and then stopped, the speed control accuracy of both deteriorates, causing abnormal tension in the rolled material 1 between them, and after the rolling rolls 2 and 3 stop, the tension This caused problems such as the inability to control the system.

Such tension control is illustrated in FIG. 4. In the figure, when the rolling roll 2 is decelerated from time _t1 , the downstream rolling roll 3 is also decelerated accordingly, and both maintain the same speed. They will gradually stop in parallel. At this time, as shown by the solid line in Figure b, the rolling roll 2 stops slightly earlier than the stopping time t3 of the rolling roll ₃ , so the tension of the rolled material 1 between them becomes greater than when it is flowing down, and a large The rolling rolls 2 and 3 came to a stop in a state where the tension was latent (see a in the figure), and sometimes the rolled material 1 even broke.

Therefore, by delaying the stopping time of the rolling roll 2 from that of the other rolling roll ₃ , the rolling roll 2 is controlled so that the tension between the rolling rolls 2 and 2 is stopped in a state smaller than that at the time of rolling. 1 breakage, etc. (broken line in Figure 4).

Even if the tension on the rolled material 1 could be controlled in this manner, variations in the plate thickness due to variations in tension between the two could not be avoided.

The present invention has been made to solve the above-mentioned problems, and by accurately controlling the tension between the rolling rolls 2 and 3 during low-speed driving until they come to a halt, the rolling material can be improved. The purpose of this is to suppress fluctuations in plate thickness and further suppress breakage of the rolled material.

[Means for solving problems]

The present invention detects the tension of the rolled material between the rolling rolls, and provides between the rolling rolls a roll whose contact pressure with the rolled material changes depending on the amount of deviation between the detected value and the target value. It is something.

[Effect]

According to the present invention, even if tension fluctuation occurs in the rolled material between the rolling rolls when the rolling mill is stopped, the rolls change the contact pressure against the rolled material in accordance with the amount of variation, thereby increasing the tension in the rolled material. Since this is controlled, it is possible to suppress the degree of change in tension in the rolled material, thereby suppressing variations in plate thickness.

〔Example〕

The present invention will be explained below based on the embodiments shown in FIGS. 1 and 2. Note that the same reference numerals are given to the same or equivalent parts as in the conventional art. In the figure, 10a, 10b
are damming rolls arranged from above the rolled material 1 on the upstream and downstream sides of the tension detector 4, and a hydraulic cylinder 11 is connected to the upstream damming roll 10a to move the damming roll 10a up and down to change the contact pressure on the rolled material 1. The tension can be adjusted by adjusting the tension. 12 is a position detector that detects the position of the damming roll 10a from the operating state of the hydraulic cylinder 11, and 13 is a position detector that detects the inclination angle θ ₁ (see FIG. 2) of the rolled material 1 with respect to the horizontal direction from the position signal detected by the position detector 12. At the same time, upon receiving a detection signal indicating the vertical downward force F (see the same figure) detected by the tension detector 4, this force F and the inclination angles θ ₁ and θ ₂ are calculated.
This is a tension detection device that calculates the tension of the rolled material 1 from the following equation.

T=F/sinθ ₁ +sinθ ₂ ... 14 receives the tension determined by the formula as the detected tension (T _FBK ) and the target tension (T _REF )
A comparator 15 receives the signal from the comparator 14 and calculates the difference between the two, and 15 is a proportional integration device that receives the deviation amount sent from the comparator 14. The signal sent by the proportional integration device 15 is used to determine the position of the hydraulic cylinder as a position detection means. The control device 16 operates to control the position of the hydraulic cylinder 11 with respect to the rolled material 1, thereby adjusting the tension of the rolled material 1. Further, A is a relay as a switching means interposed between the proportional integral calculation device 7 and the speed adjustment device 8, and between the proportional integral device 15 and the hydraulic cylinder position control device 16.
is in the OFF state when the rotational speed of the rolling roll 2 is above a predetermined value, and the rolling roll 2 is rotated via the proportional integral calculation device 7, the speed adjustment device 8, and the motor 9 as in the past, and the other proportional integral calculation device The signal from 15 is cut off and a home position signal 17 is sent to a hydraulic cylinder position control device 16 to hold the damming roll 10a in a home position via the hydraulic cylinder 11. However, when the rolling roll 10a begins to rotate at an extremely low speed below a predetermined value, the relay A is turned on and the holding device 18 interposed between the proportional-integral calculation device 7 and the speed adjustment device 8 starts to perform proportional-integral calculation. A signal from device 7 passes through. Hold device 18 that inputs the signal
holds the signal from the proportional-integral calculation device 7 at the time when relay A is turned on, and sends it out to the speed adjustment device 8 and motor 9 as a stabilized signal that is not affected by external disturbances.
The rotational speed of the rolling roll 2 is controlled with high precision through. At this time, the fixed position signal 1
7 is cut off by relay A, and instead, a signal from the proportional-integral device 15 enters the hydraulic cylinder position control device 16 to change the contact position of the damming roll 10a to the rolled material 1 via the hydraulic cylinder 11. The tension in the rolled material 1 is controlled according to the formula.

As described above, when the rolling roll 2 reaches a very low speed state below a predetermined value, the proportional integral device 15, the hydraulic cylinder position control device 16, and the hydraulic cylinder 11 operate to adjust the contact position of the damming roll 10a to the rolled material 1. By moving it up and down, the tension during flowing down can be maintained in a state without much fluctuation.

At this time, since the speed of the rolling roll 2 is controlled with higher precision by operating the holding device 18, fluctuations in the tension of the rolled material 1 and, by extension, fluctuations in the thickness of the rolled material 1 can be further suppressed.

It should be noted that the present invention can be used in the entire rolling roll speed range of a rolling mill, and is even more effective when used below a certain speed as shown in FIG. 1b.

〔Effect of the invention〕

As described above, according to the present invention, even if tension fluctuation occurs in the rolled material between the rolling rolls when the rolling mill is stopped, the damming roll changes the contact pressure against the rolled material in accordance with the amount of variation, and rolls the material. In addition to controlling the tension of the material, the rolling rolls are driven by a stabilizing signal that is unaffected by external disturbances, and the speed is controlled with high precision.This makes it possible to control the thickness fluctuations of the rolled material produced by the tandem rolling machine. There are effects that can be suppressed.

[Brief explanation of the drawing]

Figures 1a and 1b are a schematic diagram of the main parts of a tandem rolling mill showing one embodiment of the present invention (Figure 1a) and an explanatory diagram showing the action of its rolling rolls (Figure 1B);
FIG. 2 is a conceptual diagram showing the principle of the present invention, FIG. 3 is a view corresponding to FIG. 1A showing a conventional apparatus, and FIG. 4 is a view corresponding to FIG. 1B showing the operation of a conventional rolling roll. In the figure, 1 is a rolled material, 2 and 3 are rolling rolls, 4 is a tension detector, 10a is a damming roll (roll), θ ₁ and θ ₂ are inclination angles, and T is tension. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1 Equipped with a plurality of rolling rolls arranged in series and a tension detector that detects tension by contacting the rolled material flowing through the rolling rolls, the rotational speed of the rolling rolls is determined by comparing the detected tension value with a reference tension value. In a tandem rolling apparatus configured to adjust the tension of the rolled material and control the tension of the rolled material, a damming roll provided in a variable contact position with the rolling roll from the side opposite to the tension detector and the position of the damming roll are detected. a position detector, and a position signal detected by the position detector to determine the angle of inclination that the rolled material forms with respect to the horizontal direction, and detect tension from the angle of inclination and the detected value of the tension detector. a tension detection device;
a position control means for variably controlling the contact position of the roll according to the amount of deviation between the detected tension value and the reference tension value; Tandem rolling, characterized in that it is equipped with a switching means for supplying a position signal to the position control means and for switching on a holding device to the driving means for the rolling roll when the rotational speed of the rolling roll is below a predetermined value. Device.