JPS62203610A - Crown controlling method for multi-stage rolling mill - Google Patents

Abstract

PURPOSE:To make sure shape control and to improve the yield of a rolling material and productivity by controlling the extent of the movement of a rolling- down device until rolling load attains a target value in accordance with the signal from a load detecting means. CONSTITUTION:The shape of a material 18 to be rolled is detected by a shape detecting means 21. The control signal is inputted to a shape control device 22 in accordance with the detected shape to stop the sheet thickness control. The target rolling load is stored into a rolling load memory device 29 in this stage. The shape control device 22 detects the rolling load by a load detector 23 and makes the shape control with the constant rolling force under the target rolling load while operating a wedge driving means 14 for crown adjustment. The shape control is surely and efficiently executed by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a crown control method for a multi-high rolling mill.

(Prior art) Conventionally, as this type of multi-high rolling mill, for example, Fig. 3, Fig. 4
A 12-high rolling mill (not shown) is known.

That is, an upper roll housing l that supports an upper roll group is fit into four pillars 3 erected in a lower roll housing 2 that supports a lower roll group so as to be able to rise and fall, and an electric motor 4 that is provided on the upper roll housing l The upper roll group is raised and lowered by the upper roll group. Each of the upper and lower roll groups includes a work roll 5.6, an intermediate roll 7.8 that supports the work roll 5.6, and a support roll 9.8 that supports the work roll 5.6.
It is composed of 9a and 10°10a. A pair of crown adjustment wedge blocks 12 and 13 are formed for each saddle 11 between each saddle 11 of the upper support roll 9a on the entry side and exit side of the rolling mill and the upper roll housing l. The wedge 13 is movable via a drive shaft 15 by a plurality of wedge drive means 14 for crown adjustment provided on the upper roll housing l.

Further, a rolling wedge block l (i, +7) is formed between the lower roll housing 2 and the support roll IO, and the rolling wedge 17 is moved by an appropriate means, making it possible to roll down the work roll 5.6. By moving the JAI trimming wedge 13, each saddle is given a different minute displacement, the crown of the work roll 5.6 is adjusted, and the planar shape of the rolled material 18 is adjusted. It's about to be controlled.

In this 12-high rolling mill, the operator operates the rolling wedge 17 as appropriate to adjust the rolling load and control the thickness of the rolled material 18, and also to control the planar shape of the rolled material 18. While observing the planar shape on the exit side of the rolling mill, determine the amount of mechanical crown (hereinafter simply referred to as crown m) to be given to the work roll 5.6, and manually drive the crown adjustment wedge drive means 1 as appropriate. The crown control of the work roll 5.6 was carried out. In addition, in order to cope with changes in the planar shape of the rolled material 18 due to steep fluctuations in thermal crown during acceleration and deceleration of the rolling mill, the amount of crown to be applied to the work rolls 5 and 6 is automatically set according to the rolling speed. A crown control method has been proposed (Japanese Patent Application No. 59-222469).

(Problems to be Solved by the Invention) However, in the manual crown control method or automatic control method, as shown in FIG.
The crown ff1M that contributes to the shape modification is small, and the remaining crown ff1M becomes an element that changes the rolling load. For this reason, even if crown control is performed on the work roll 5°6 to control the shape of the rolled material I8, the rolling load changes depending on the amount of crown, resulting in plate thickness fluctuations, making shape control impossible. In addition to this, it is necessary to control the plate thickness, and a plate thickness correction section is added to the shape correction section, increasing the number of quality defects. In addition, this plate thickness variation becomes a disturbance that disturbs the shape control, resulting in problems such as poor crown operability and poor control effects.

The present invention has been made in view of the above problems, and provides a crown control method in a multi-high rolling mill that does not cause plate thickness variation even when the crown amount of a work roll is changed in order to control the shape of a rolled material. The purpose is to

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a method for controlling the thickness of the rolled material and the shape of the material to be rolled. In a crown control method for a multi-high rolling mill in which the crown amount of a work roll is adjusted based on a signal from a shape detection means, thickness control is stopped at the start of shape control, and at the same time the rolling load is adjusted based on a signal from a load detection means. is stored as a target value, and constant pressure vitality control is performed to control the rolling load to the target value by adjusting the movement amount of the rolling device based on the signal from the load detection means,
This is to control the shape while compensating for Nli variations in plate thickness due to changes in rolling load caused by the straightening of the crown m.

(Example) Next, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 applies the crown control method according to the present invention!
The control system of the two-high rolling mill is shown, and the main body portion of the 12-high rolling mill in the figure has substantially the same structure as the conventional one, and corresponding parts are given the same numbers and explanations are omitted.

The control system consists of three systems: a shape control system, a plate thickness control system, and a constant pressure vitality control system.

The shape control system includes a shape detection means 21 that detects the planar shape of the rolled material 18 provided on the exit side of the rolling mill, and drives the crown adjustment wedge drive means 14 based on a signal from the shape detection means 2I. Due to work roll 5.6
and a shape control device 22 that controls the surface shape of the rolled material 18 by adjusting the crown of the rolled material 18.

The plate thickness control system includes a load detector 23 provided on the support column 3 and a rolling load manual section 2 that inputs signals from the load detector 23.
4, an arithmetic unit 25 that calculates the amount of movement of the rolling wedge 17 based on the signal from the rolling load input section 24, and an amplifier 26 that amplifies the control signal from the arithmetic unit 25.
It is comprised of a servo valve 27 that converts the electric control signal from the amplifier 26 into an llI+ pressure control signal to move the lowering wedge 17.

The constant pressure vitality control system includes the rolling load input section 2 of the plate thickness control system.
4, the signal from now on is received via the switch 28, and the rolling load storage section 29 stores the signal at the time when the switch 28 is turned off, and the signal from this rolling load storage section 29 is targeted. As a value, the rolling load input section 2
The controller 30 generates a control signal based on the signal from the controller 4 to obtain the target rolling load, and inputs this control signal to the amplifier 26 of the plate thickness control system.

Note that switches 31 and 32 are provided between the arithmetic unit 25 and the amplifier 26 of the plate thickness control system, and between the regulator 30 and the amplifier 26 of the constant pressure vitality control system, respectively.
In addition, it is turned on and off based on a signal from the shape control device 22 of the shape control system.

In the control system having the above configuration, prior to controlling the shape of the material to be rolled 18, the plate thickness is controlled.

First, based on the signal from the shape control device 22 to which no control signal is input, the switch 3! is turned ON to close the plate thickness control system, and the switch 32 is turned OFF to open the constant pressure vitality control system, but the switch 28 remains ON and the rolling load storage section 29 is activated. Then, according to the plate thickness control system, plate thickness control is performed to obtain a target plate thickness.

That is, the rolling load acting on the rolled material 18 is detected by the load detector 23 as a reaction force generated on each support column 3, and is manually inputted to the calculation section 25 via the rolling load input section 24. The calculation unit 25 calculates a control amount from the manually applied rolling load and mill constant, and outputs it as the amount of movement of the rolling wedge 17. And this pressure reduction wedge! An output signal corresponding to the amount of movement 7 is manually inputted to the servo valve 27 via the amplifier 26 to move the reduction wedge 17. As a result, plate thickness control is executed to obtain the target plate thickness. This plate thickness control method was devised at the British Steel Research Institute, and is abbreviated as B.
This is called the ISIIA method.

Next, assuming that the plate thickness reaches the target value through the plate thickness control, the plate thickness control system is opened to control the shape of the rolled material 18, but with the crown adjustment of the work roll 5.6 in the shape control, In order to compensate for changes in plate thickness due to changes in rolling load, constant pressure vitality control is performed in which the constant pressure vitality control system is closed simultaneously with the start of shape control to maintain the rolling load at the rolling load immediately before starting shape control. Hereinafter, this shape control and constant pressure vitality control will be explained according to the flowchart shown in FIG.

In the shape control system, the shape detection means 21 detects the rolled material +
When the shape of 8 is detected and a control signal is inputted to the shape control device 22 based on this (step 1), upon receiving the signal from the shape control device 22, switches 3I and 28h4 are turned off.
The switch 32 is turned on. Here, switch 3I is set to O.
When FF is reached, the plate thickness control system is opened and plate thickness control is stopped (step 2). Is switch 28 OI? When F is reached, the signal from the rolling load input section 24 is cut off, and the signal immediately before the cutoff, that is, the rolling load immediately before the plate thickness control is stopped, is stored in the rolling load storage section 29 (step 3). When the switch 32 is turned on, the constant pressure vitality control system is closed (step 4).

A shape control device 2 that receives control signals from the shape control system.
2 operates the crown adjusting wedge driving means 14 by calculating the control amount. As a result, the crown of the work roll 5.6 is adjusted and the shape of the rolled material 18 is corrected (Step 5), while the rolling load changes due to the excess crown amount and the plate thickness fluctuates (Step 6). .

Therefore, in order to compensate for this plate thickness variation, constant pressure vitality control is performed (step 7). That is, similarly to the plate thickness control system, the rolling load detected by the load detector 23 and the rolling load as a target value stored in the rolling load storage section 29 are compared, and the control deviation is calculated by the controller 30. After converting the input into the movement m of the reduction wedge I7, the reduction wedge 17 is made to move 4 times via the amplifier 2G and the sarpo valve 27. As a result, even if the crown adjustment is performed, the rolling load is maintained constant, and variations in plate thickness caused by the crown operation are eliminated.

Then, when the shape control of the rolled material 18 is performed under this constant pressure vitality control and a predetermined planar shape is obtained, it is determined whether or not to end the shape control (step 8), and the shape control is continued. If so, return to step 5 and repeat the same steps, and if the plate thickness control is to be performed after completion, switch 32 is turned OFF'F and switches 28 and 31 are turned ON. Here, when the switch 32 is turned OFF and the switch 28 is turned ON, the constant rolling force control system is opened (
Step 9), the memory of the rolling load storage section 29 is erased (
In step 10), a new signal from the rolling load input section 24 is received. Also, when the switch 31 is turned ON, the plate thickness control system is closed and the plate thickness control is resumed (
Step 11).

Furthermore, if some disturbance occurs during plate thickness control and an abnormality is observed in the planar shape, it is determined whether or not to start shape control (step 12). Returning to step 1, similar steps are repeated, and if shape control is not required, return is made to step 11 to continue plate thickness control.

In the above embodiment, a plate thickness control method based on the ntSIA method was used as the plate thickness control system, and a part of the control system was used as the constant rolling force control system.
A forward AGC method, a tension AGC method, a speed AGC method, etc. may be used.

(Effects of the Invention) As is clear from the above description, according to the present invention, even if crown adjustment is performed in shape control, the rolling load does not change and the plate thickness does not vary.

Therefore, even when the operator manually controls the shape, the operability of the crown is improved, and the control effect is extremely high. In addition, since shape control and plate thickness control can be performed simultaneously, the number of quality defects that previously occurred in the shape correction area and plate thickness correction area is significantly reduced, and the defective rate of the product is reduced. This has the effect of improving yield and increasing productivity.

[Brief explanation of drawings]

Fig. 1 is a control block diagram of a 12-high rolling mill to which the method according to the present invention is applied, Fig. 2 is its flowchart, and Fig. 3 is a control block diagram of a 12-high rolling mill to which the method according to the present invention is applied. Partially cutaway side view of the two-high rolling mill, Figure 4 is the 3rd
The sectional view taken along the line 1-1 in the figure and FIG. 5 are diagrams for explaining the influence of the crown amount on plate thickness control and shape control. 5.6...Work roll, 13...Wedge for crown adjustment, 14...Wedge drive means for crown adjustment,
17... Wedge for rolling, 18... Material to be rolled, 21
... shape detection means, 22 ... shape control device, 23.
...Load detector, 24...Rolling load input section, 26...
- Amplifier, 27... Servo valve, 29... Rolling load storage section, 30... Adjuster. Patent applicant Kobe Steel Co., Ltd. Agent Patent attorney Aohaku Ao and 2 others Figure 2

Claims (1)

[Claims] (1) Multi-stage rolling in which the thickness of the material to be rolled is controlled and the amount of crown of the work roll is adjusted based on a signal from a shape detection means provided on the exit side of the rolling mill in order to control the shape of the material to be rolled. In a crown control method for a machine, at the same time as stopping plate thickness control at the start of shape control, a rolling load based on a signal from a load detection means is stored as a target value, and the rolling force is activated based on a signal from the load detection means. Constant rolling force control is performed to control the rolling load to the target value by adjusting the amount of movement of the crown, and shape control is performed while compensating for fluctuations in plate thickness due to changes in rolling load caused by adjusting the crown amount. Features a crown control method for multi-high rolling mills.