JPH08117823A - Method for correcting gap and controller of rolling mill equipped with horizontal bending mechanism - Google Patents

Abstract

PURPOSE: Not to vary a gap between working rolls even when operating a bending cylinder by memorizing a rolling load and adjusting a hydraulic drawing down force for rolling with a memorized value so that the varied quantity of a rolling load during the operation of the bending cylinder becomes the minimum. CONSTITUTION: Rolling working is performed by working rolls 1 and 2, and the crowns of the working rolls 1 and 2 are controlled by horizontal pushing devices 12 and 13. The rolling loads of the working rolls 1 and 2 before the crowns are controlled by a hydraulic drawing down controller 24, are memorized by a memory. When the horizontal pushing devices 12 and 13 are worked to control the crowns, the rolling loads of the working rolls 1 and 2 are varied. The varied rolling loads are compared with the rolling loads memorized by a memory 24a with the hydraulic drawing down controller 24, and a hydraulic drawing down force for rolling is increased and decreased so that an original rolling load is attained. Therefore, influence such as mechanical hysteresis, the hysteresis of a pressure in a bending cylinder, etc., is eliminated, and a variation in plate thickness can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gap correction method and control device for a rolling mill having a horizontal bending mechanism for work rolls.

[0002]

2. Description of the Related Art Conventionally, as illustrated in FIG. 4, one of upper and lower work rolls 1 and 2 (upper work roll 1 in the figure) is formed to have a small diameter, and the upper work roll 1 is offset in the rolling line direction. Along with the upper work roll 1, an intermediate roll 3, a pressing roll 4 and a bending cylinder 5 are provided.
A rolling mill has been developed in which the upper working roll 1 is bent horizontally by the bending cylinder 5 via the pressing roll 4 and the intermediate roll 3 to correct the vertical roll crown of the upper working roll 1 (for example, Fairness 3-18
003, Jikken 4-9042). However, in a conventional rolling mill equipped with such a horizontal bending mechanism, since the upper and lower work rolls have different diameters, there is a problem in that the surface properties (roughness and gloss) of the rolled sheet material differ.

Therefore, as illustrated in FIG. 5, the upper and lower work rolls 1 and 2 of the same diameter of the rolling mill, which are rolled under hydraulic pressure, are offset in the rolling line direction so that both work rolls 1 and 2 are horizontal. A rolling machine that bends to the side has been proposed.
In such a rolling mill, the horizontal force F acting on the work rolls 1 and 2 by the initial offsets (center misalignment in the rolling direction) of the backing roll 6, the intermediate roll 7, and the work rolls 1 and 2 respectively.
A plurality of pairs (for example, 6 pairs) of horizontal pressing devices 8 in the axial direction of the work rolls 1 and 2 (the direction perpendicular to the paper surface) so as to face each other.
With this horizontal pressing device 8, the work rolls 1, 2 are
The work rolls 1 and 2 are bent horizontally by applying a horizontal pushing force to each part in the axial direction.

A plurality of pairs of horizontal pressing devices 8 are composed of a pressing roll 4, an intermediate roll 3 and a bending cylinder 5 as in FIG. 4, and the bending cylinder 5 has a displacement detection for detecting the displacement of the piston rod. The device 9 is incorporated. In such a conventional rolling mill, the change in the clearance on the hydraulic pressure side is calculated from the change in the position of the bending cylinder so that the gap between the work rolls does not change even if the bending cylinder 5 is operated for crown control. In accordance with this, control (gap correction control) for moving the backup roll 6 has been performed.

[0005]

However, in such a conventional gap correction control, the degree of influence on the gap change differs depending on each bending cylinder and rolling load, and when there is hysteresis in the mechanical structure, the cylinder position change or There is a problem that the degree of influence varies depending on the direction of pressure change. for that reason,
There is a problem that the gap correction effect with respect to the condition change is small, and the amount of test required for checking the influence degree is enormous.

In other words, in the conventional control in which the auxiliary roll 6 is moved from the displacement of the bending cylinder 5, the upper and lower work rolls 1 and 2 may not move as calculated, and therefore, the bending cylinder 5 is used for crown control. There is a problem in that the gap between the work rolls may change when the is operated.

The present invention was created to solve such problems. That is, an object of the present invention is to provide a gap correction method and a control device for a rolling mill provided with a horizontal bending mechanism in which a gap between work rolls does not change even when a bending cylinder is operated for crown control. It is in.

[0008]

According to the present invention, the rolling load before the operation of the bending cylinder of a rolling mill, which performs the rolling reduction under the hydraulic pressure, is stored, and the rolling during the operation of the bending cylinder is performed with respect to the stored rolling load. When the rolling load in operation is higher than the memorized rolling load, the hydraulic rolling reduction force is reduced so that the change amount of the load is minimized, and when the rolling load in operation is lower than the memorized rolling load. Provided is a gap correction method for a rolling mill having a horizontal bending mechanism, which is characterized in that a hydraulic rolling force for rolling is increased.

Further, according to the present invention, the rolling load before the operation of the bending cylinder of the rolling mill, in which the rolling reduction is performed under the hydraulic pressure, is stored, and the variation of the rolling load during the operation of the bending cylinder is stored with respect to the stored rolling load. So that
Hydraulic pressure reduction control for reducing the rolling hydraulic pressure reduction force when the rolling load in operation is higher than the memory rolling load, and increasing the hydraulic pressure reduction force for rolling when the rolling load in operation is lower than the memory rolling load An apparatus for controlling a rolling mill having a horizontal bending mechanism is provided.

[0010]

According to the above-described method and apparatus of the present invention, the rolling load before the operation of the bending cylinder of the rolling mill, in which the rolling reduction is performed under the hydraulic pressure, is stored, and the rolling load is operated so as to maintain this load. The rolling reduction is reduced when the rolling load is high and the rolling reduction is increased when the rolling load is lower than the memory rolling load to minimize the change in rolling load. Therefore, it is possible to maintain the rolling load and reduce the plate thickness variation without considering the influence of the hysteresis of the mechanical system, the hysteresis of the pressure in the bending cylinder, and the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the drawings, common parts are designated by the same reference numerals and used. FIG. 1 is a configuration diagram of a rolling mill provided with a horizontal bending mechanism to which the method of the present invention is applied,
FIG. 2 is a plan view of the lower half thereof. 1 and 2, the rolling mill 10 has upper and lower work rolls 1 and 2 having the same diameter offset in the rolling line direction so that both work rolls 1 and 2 are offset.
2 is a rolling machine that bends horizontally, and the horizontal force F that acts on the work rolls 1 and 2 by the initial offset (center deviation in the rolling direction) of each of the backing roll 6, the intermediate roll 7, and the work rolls 1 and 2 is applied. As opposed to each other, a plurality of pairs (six pairs in the figure) of horizontal pressing devices 12 and 13 (13-1 to 13-6 on the lower side) in the axial direction of the work rolls 1 and 2 (direction perpendicular to the paper surface). The horizontal pressing devices 12 and 13 are configured to apply a horizontal pressing force to each axial portion of the work rolls 1 and 2 to bend the work rolls 1 and 2 horizontally. The plurality of pairs of horizontal pressing devices 12 and 13 include a pressing roll 4, an intermediate roll 3, and bending cylinders 14 and 15 (1 on the lower side).
5-1 to 15-6), and the bending cylinders 14 and 15 incorporate a displacement detection device 9 (FIG. 1) for detecting the displacement of the piston rod 16a.

In FIG. 1, a displacement detecting device 9 includes a magnetic rod 9a (trade name: Magnescale) whose one end is fixed to a piston rod 16a, and a displacement which is fixed to a cylinder body 16b and axially penetrates the magnetic rod 9a. Detector 9b
(Magnet scale head), the amount of displacement of the piston rod 16a can be detected via a magnet scale detector incorporated in the control device.

FIG. 3 is a control block diagram showing a control method of the rolling mill of FIG. In this drawing, a rolling mill 10 is provided with a load cell 21 for detecting the rolling load thereof and a roll moving cylinder 22 for vertically moving the auxiliary roll 6 so as to face each other with each roll interposed therebetween. The roll moving cylinder 22 includes a piston rod 22
A displacement detection device 9 for detecting the displacement of a is incorporated.

In FIG. 3, the rolling mill 10 further includes a hydraulic pressure reduction control device 24 for controlling hydraulic pressure reduction and a horizontal pressing device 1.
The horizontal pressing force control device 26 for controlling the pressure control devices 2 and 13 is provided. According to the present invention, the hydraulic pressure reduction control device 24 stores the rolling load detected by the load cell 21 before the operation of the bending cylinders 14, 15 of the rolling mill that performs the rolling reduction under the hydraulic pressure, and stores the rolling load against the stored rolling load. When the rolling load during operation is higher than the memorized rolling load, the hydraulic rolling force for rolling is reduced so that the amount of change in the rolling load during operation of the bending cylinders 14 and 15 is minimized, so that the rolling cylinder operates above the memorized rolling load. The servo amplifier 24b and the servo valve 24 increase the rolling hydraulic rolling force when the rolling load is low.
The gap on the hydraulic pressure lower side is moved via c. After the operation of the bending cylinders 14 and 15 is completed, the control position is maintained, and when the bending cylinders 14 and 15 are operated again, similarly, the rolling load immediately before the start is stored in the memory 24a, and the stored rolling force is stored. When the rolling load during operation is higher than the memory rolling load, the hydraulic rolling reduction force for rolling is reduced so that the amount of change in the rolling load during operation of the bending cylinders 14 and 15 with respect to the load is minimized. When the rolling load during operation is lower than that, the gap on the hydraulic pressure reduction side is moved via the servo amplifier 24b and the servo valve 24c so as to increase the hydraulic pressure reduction force for rolling. According to such a method, the rolling load before the operation of the bending cylinder of the rolling mill, which performs the rolling reduction under the hydraulic pressure, is stored, and this rolling load is maintained so that the rolling load during operation is high with respect to the stored rolling load. By reducing the rolling hydraulic rolling force and increasing the rolling hydraulic rolling force when the rolling load during operation is lower than the memorized rolling load, the amount of change in rolling load is minimized. It is possible to maintain the rolling load and reduce the plate thickness variation without considering the influence of the pressure in the cylinder such as hysteresis.

The horizontal pushing force control device 26 includes the load cell 21.
The pressure of each bending cylinder is set by the pressure setting calculator 26a from the rolling load detected by, and the bending cylinder is operated by the servo valve 26b until the set displacement corresponding to this pressure is reached. The amount of displacement by the device 9 is fed back to control the crown by moving each bending cylinder without changing the entire rolling load.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0017]

As described above, the gap correction method and control device for a rolling mill provided with the horizontal bending mechanism according to the present invention has a gap (gap) between work rolls even if the bending cylinder is operated for crown control. Does not change, and has an excellent effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a rolling mill equipped with a horizontal bending mechanism to which the method of the present invention is applied.

FIG. 2 is a plan view of the lower half of FIG.

FIG. 3 is a control block diagram showing a control method of the rolling mill of FIG. 1.

FIG. 4 is a configuration diagram of a rolling mill provided with a conventional horizontal bending mechanism.

FIG. 5 is a configuration diagram of a rolling mill provided with a horizontal bending mechanism vertically.

[Explanation of symbols]

 1, 2 Work roll 3 Intermediate roll 4 Pressing roll 5 Bending cylinder 6 Holding roll 7 Intermediate roll 8 Horizontal pressing device 9 Displacement detecting device 9a Magnetic rod 9b Detector 10 Rolling machine 12, 13 Horizontal pressing device 14, 15 Bending cylinder 16a Piston rod 16b Cylinder body 21 Load cell 22 Roll moving cylinder 22a Piston rod 24 Hydraulic reduction control device 24a Memory 24b Servo amplifier 24c Servo valve 26 Horizontal pressing force control device 26a Pressure setting calculator 26b Servo valve F Horizontal force

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical indication location B21B 13/14 L 29/00 A 37/58 8315-4E B21B 37/00 144 (72) Inventor Makoto Mouth Kanagawa Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Ichi, Ishikawajima-Harima Heavy Industries Co., Ltd. Yokohama Engineering Center (72) Inventor Junji Koshiro Marunouchi 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan KK (72 ) Inventor Tatsuo Toyofuku, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (2)

[Claims] 1. A rolling load before rolling of a bending cylinder of a rolling mill, in which rolling is performed under hydraulic pressure, is stored, and a change amount of the rolling load during operation of the bending cylinder is minimized with respect to the stored rolling load. Reducing the hydraulic rolling reduction force when the rolling load in operation is higher than the memory rolling load, and increasing the hydraulic rolling reduction force when the rolling load in operation is lower than the memory rolling load, Gap correction method for a rolling mill equipped with a horizontal bending mechanism. 2. The rolling load before the operation of the bending cylinder of the rolling mill, which performs the rolling reduction under the hydraulic pressure, is stored, and the change amount of the rolling load during the operation of the bending cylinder is minimized with respect to the stored rolling load. A hydraulic pressure reduction for reducing the rolling hydraulic pressure reduction force when the rolling load in operation is higher than the memory rolling load, and increasing the hydraulic pressure reduction force for rolling when the rolling load in operation is lower than the memory rolling load A control device for a rolling mill having a horizontal bending mechanism, the control device comprising a control device.