JPH059167B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a loop control method for rolled materials in a multi-high rolling mill, and sometimes involves loop control of rolled materials such as wire rods, steel bars, shaped steel, or non-ferrous strips. This relates to loop (sag) control.

[Prior Art] This type of loop control device uses a loop detector to detect the loop amount, and uses this detection signal to perform speed control to reduce the loop amount before the exit stand exits. It is known that the structure is configured to remove the .

FIG. 2 shows an example of the configuration of a conventional loop control device. In FIG. 2, reference numeral 10 indicates a loop amount detector, which is configured to detect the loop amount of the rolled material 16 between a predetermined entry rolling stand 12 and exit rolling stand 14. The loop amount detection signal detected by the loop amount detector 10 is processed by a signal converter 18, fed back to a loop adjuster 20, and compared with a set value to adjust the input side rolling stand 12 so that a predetermined loop amount is obtained. Adjust and control the speed. In this case, contacts 22, 24, and 26 for selectively inputting the detected value and set value of the loop amount to the loop regulator 18 are provided on the appropriate control line. Further, as a means for adjusting the speed of the entry side rolling stand 12, a speed regulator 30, which controls the speed of the rolling roll drive motor 28 of the entry side rolling stand 12 based on the output signal of the loop regulator 20, and a current A regulator 32 and a firing angle regulator 34 are provided, and a speed detector 36 is provided.
A known motor control system configured to provide a feedback control signal is employed.

[Problems to be Solved by the Invention] However, in the conventional loop control device, the contact operations for inputting the detected value and set value of the loop amount to the loop regulator 20 are set as follows. That is, the contact 26 is turned ON during loop control and inputs the detected value of the loop amount to the loop regulator 20. Further, the contact 22 is turned on during normal loop control to input the detected value of the loop amount to the loop regulator 20. Furthermore, the contact 24
is turned on to control the loop amount when the rear end of the rolled material 16 passes between the stands. Therefore, conventionally, the contact point 24
The loop amount for input to the loop regulator 20 via is set to zero. However, in this case, even if the contact 24 is turned ON, the loop amount cannot be completely reduced to zero, and especially in the case of high-speed rolling, a significant amount of loop remains, and the tail end of the rolled material may be whipped. , the tail end gets caught in the guide in front of the rolling roll, causing the tip of the next material to collide with the remaining material, causing rolling failure, and furthermore, the end of the material to be rolled falls through, causing excessive overshoot of the rolling mill. There are some drawbacks such as:

An object of the present invention is to overcome the problems of the conventional loop control device described above, by reducing the loop amount to zero before the trailing end of the rolled material runs between the stands, thereby suppressing overshoot in the motor speed. The present invention provides a loop control method for rolled material in a multi-high rolling mill.

[Means for Solving the Problems] A loop control method for rolled material in a multi-high rolling mill according to the present invention detects the loop amount of the rolled material between predetermined stands, and controls the rolled material based on the detected loop amount value. The speed of the electric motor that drives the entrance stand is controlled so that the loop amount is always constant, and the speed of the electric motor is controlled by setting the loop amount to zero when the rolled material passes between the rear end stands. In the loop control device for rolled material in the configured multi-high rolling mill, the loop amount set value when the rear end of the rolled material passes between the stands is set to a value that has the same absolute value as the loop amount set value during loop control and has positive and negative polarity. The motor is characterized by having a set value of opposite polarity, which is the only opposite polarity, and rapidly speeding up the motor.

[Function] The method for controlling the loop of rolled material in a multi-high rolling mill of the present invention is to detect the loop amount of the rolled material between the stands with a detector, and to adjust the deviation between this detected value and a set value via a loop amount adjuster. Adjustment control can be performed to an appropriate loop amount. In this case, when the rear end of the rolled material passes between the stands, the loop amount adjuster
By inputting a set value of opposite polarity, which has the same absolute value as the loop amount set value during normal rolling but is opposite only in positive and negative polarity, the speed set value is rapidly lowered and the motor is suddenly decelerated. This makes it possible to reduce the loop amount to zero and easily control speed overshoot.

[Example] Next, an example of a loop control method for a rolled material in a multi-high rolling mill according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a system diagram of a control device that implements the loop control method of the present invention. The configuration of the control device of this embodiment is the same as the system diagram of the conventional control device shown in FIG. 2 described above. Therefore, for convenience of explanation, the same components are given the same reference numerals and detailed explanation thereof will be omitted. Therefore, the basic operation of the device of this embodiment is the same as that of the conventional device.

That is, the loop amount detection signal detected by the loop amount detector 10 is processed by the signal converter 18, fed back to the loop adjuster 20, and compared with a set value, the input side rolling stand is adjusted to a predetermined loop amount. Adjust and control 12 speeds. However,
In this case, in the conventional device, in order to control the loop amount when the rear end of the rolled material passes between the stands, the loop amount input via the contact 24 is set to zero, but in the present invention, the loop amount input via the contact 24 is set to zero. , the loop amount is inputted through the contact 22 during loop control, and a setting value of the opposite polarity, which has the same absolute value and is opposite only in positive and negative polarity, is input. be.

In this way, for loop regulator 20, contact 2
Since the loop regulator 20 is a PI regulator, by inputting the loop amount set value of the opposite polarity through 4, the output of the loop regulator 20 changes from the output during normal loop control to the loop amount zero setting. It is possible to reduce the output more rapidly. As a result, the speed setting value to the speed regulator 30 is lowered, and the
The drive torque can be suddenly reduced with respect to the load torque of
The speed of the loop can be suddenly reduced and the loop amount can be easily reduced to zero.

[Effects of the Invention] As is clear from the embodiments described above, according to the present invention, when the trailing end of the rolled material passes between the stands, the loop amount setting value is absolutely different from the loop amount setting value during normal loop control. By setting the setting values of opposite polarity, where the values are the same and only the positive and negative polarities are opposite, it is possible to rapidly reduce the speed setting value of the motor on the entry side stand, causing the motor to suddenly decelerate, and as a result, the loop amount can be set to zero to suppress speed overshoot.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a control device that implements a method for loop control of rolled material in a multi-high rolling mill according to the present invention, and FIG. 2 is a diagram illustrating a loop control method for rolled material in a multi-high rolling mill for explaining a conventional loop control method. It is a system diagram of a device. 10... Loop amount detector, 12... Entry side stand, 14... Output side stand, 16... Rolled material, 1
8...Signal converter, 20...Loop regulator, 2
2, 24, 26... Contact, 28... Electric motor, 30
...Speed regulator, 32...Current regulator, 34...
Firing angle adjuster, 36...speed detector.

Claims (1)

[Claims] 1. Detecting the loop amount of the rolled material between predetermined stands, and controlling the speed of the electric motor that drives the entrance stand so that the loop amount of the rolled material is always constant based on the detected loop amount value. In a loop control device for a rolled material in a multi-high rolling mill configured to control the speed of the electric motor by setting a loop amount to zero when the rear end of the rolled material passes between the stands, The loop amount set value when the end passes between the stands is set to an opposite polarity set value that has the same absolute value as the loop amount set value during loop control, but only the positive and negative polarities are opposite, and the motor is suddenly decelerated. A loop control method characterized by: