JPH06262230A - Method for controlling elongation percentage in skin pass rolling mill - Google Patents

Abstract

PURPOSE:To enable highly accurate skin pass rolling by executing feedforward control of rolling load and rolling tension in a skin pass rolling mill by adding the amount of correction due to rolling conditions to the amount of correction for compensating the fluctuation in elongation percentage due to the fluctuation in rolling speed. CONSTITUTION:At the time of skin pass rolling, rolling load and rolling tension based on the rolling conditions of the size of sheet, kinds of steel, roughness and elongation percentage, etc., are preset in the skin pass rolling mill 1. After presetting, when skin pass rolling is executed by driving the skin pass rolling mill 1, tensions at rolls 4 on the inlet side of the rolling rolls 2, 3 are automatically adjusted with an automatic tension controller 5 and skin pass rolling of a steel strip is executed. At this time, the elongation percentage control in the skin pass rolling mill 1 is executed with an elongation percentage controller 6, the rolling load and tension of the skin pass rolling mill 1 is controlled by feedback and the skin pass rolling of the steel strip is executed. Aside from this, the rolling load and tension of the skin pass rolling mill 1 is directly controlled by feedforward by the amount of correction for compensating the fluctuation in elongation percentage due to rolling speed. In this way, the fluctuation in elongation percentage due to the fluctuation in rolling speed is restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elongation control method for a temper rolling mill, which controls fluctuations in elongation caused by fluctuations in rolling speed during temper rolling of a steel strip.

[0002]

2. Description of the Related Art Conventionally, temper rolling mills are
The rolling load and rolling tension were preset according to the rolling conditions such as roughness and elongation, and the temper rolling was performed while performing the elongation control by feedback controlling the rolling load and rolling tension of the temper rolling mill. . However, if the rolling speed changes, the elongation of the steel strip changes, so the rolling speed is introduced into the rolling conditions such as plate size, steel type, roughness, and elongation to suppress the variation in elongation. Although it is also considered that it is difficult to estimate the proper condition in each case, even if the proper condition can be estimated, it is too complicated and there is a problem in maintainability.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to improve the rolling accuracy by correcting the elongation variation caused by the variation of rolling speed during temper rolling.

[0004]

Means for Solving the Problems The present invention performs elongation control by feedback control of rolling load and rolling tension of a temper rolling mill, and a correction amount for compensating for elongation fluctuation due to fluctuation of rolling speed, It is characterized in that the rolling load and rolling tension of the temper rolling mill are feed-forward controlled by adding a correction amount according to rolling conditions.

[0005]

[Operation] When elongation changes due to changes in rolling speed during temper rolling of a steel strip for which elongation is controlled, a correction amount for compensating for elongation changes due to changes in rolling speed, and a correction amount depending on rolling conditions In addition to the above, the rolling load and rolling tension of the temper rolling mill are feed-forward controlled to suppress the change in elongation rate due to the change in rolling speed to be small and improve the rolling accuracy.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the illustrated embodiments. Reference numeral 1 is a temper rolling mill provided with rolling rolls 2 and 3 and an input side roll 4 and an output side roll 4a sandwiching the rolling rolls 2 and 3, respectively. The rolling tension is automatically adjusted by the automatic tension control device 5 provided on the rolls 2 and 3. Reference numeral 6 is an elongation control device for feedback-controlling the rolling load and rolling tension of the temper rolling mill. The elongation control device 6 is for the rolling tension of the inlet roll 4 and the outlet roll 4a and the rolling tension of the rolling rolls 2 and 3. And to control the rolling load. Therefore, temper rolling mill 1
Is the one in which the rolling load and rolling tension are preset based on the rolling conditions such as plate size, steel type, roughness, specified elongation, etc., and during normal rolling, the rolling load and rolling tension are feedback-controlled to control the elongation. Is.

Further, the temper rolling mill 1 adds a correction amount according to rolling conditions such as plate size, steel type, roughness, and specified elongation to the correction amount for compensating for the change in elongation due to the change in rolling speed to obtain the rolling load. The rolling tension is feed-forward controlled, and the rolling rolls 2 and 3 of the temper rolling mill 1, the inlet roll 4, and the outlet roll 4a are controlled in rolling load or rolling tension in accordance with fluctuations in rolling speed. It The relationship between the rolling speed and the feed-forward controlled correction amount is set based on the actual data as shown in the graph of FIG. Further, the correction amount of the feedforward control due to the fluctuation of the rolling speed applied to the temper rolling mill 1 is different depending on the rolling conditions such as the sheet size, the steel type, the roughness and the elongation, so the correction amount based on the actual data is added. The accuracy is improved.

In the temper rolling device thus constructed, a rolling load and a rolling tension based on rolling conditions such as sheet size, steel type, roughness and elongation are preset in the temper rolling mill 1.
After the presetting, if the temper rolling mill 1 is driven to perform temper rolling, the automatic tension control device 5 causes the rolling rolls 2,
3. The temper rolling of the steel strip is performed while the tension of the entry side roll 4 is automatically adjusted. At this time, the temper rolling mill 1 is elongation controlled by the elongation control device 6, the rolling load and rolling tension of the temper rolling mill 1 are feedback-controlled, and the temper rolling of the steel strip is performed.

The rolling speed, that is, the temper rolling mill 1
When the output side actual speed of the rolls fluctuates, a correction amount that ignores the elongation control by the elongation control device 6 and compensates for the fluctuation of the elongation depending on the rolling speed is added to the temper rolling mill 1 and the temper rolling is performed. Feed forward control of the rolling load and rolling tension of the machine 1 is performed. The correction amount that compensates for the change in elongation is the plate size, steel type,
Since the rolling conditions such as roughness and elongation vary depending on the rolling conditions, the rolling accuracy is improved by feed-forward controlling the rolling load and rolling tension by adding the correction amounts according to these rolling conditions to the correction amounts.

[0010]

As is apparent from the above description, the present invention uses feedback control of the rolling load and rolling tension of the temper rolling mill during normal rolling in order to suppress changes in the elongation of the steel strip due to changes in rolling speed. Apart from elongation control,
The feed-forward control, in which the correction amount that compensates for the elongation change due to the rolling speed is added directly to the rolling load and rolling tension of the temper rolling mill, suppresses the elongation change due to the rolling speed fluctuation and achieves a highly accurate adjustment. It is possible to carry out quality rolling, and it is extremely significant to bring to the industry as a method for controlling the elongation of a temper rolling mill that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a schematic side view of a temper rolling mill of the present invention.

FIG. 2 is a flowchart of the elongation control method of the present invention.

FIG. 3 is a graph showing the relationship between rolling speed and correction amount in the present invention.

[Explanation of symbols]

 1 Temper rolling mill 4 Automatic tension controller 5 Elongation controller

Claims (1)

[Claims] 1. A feedback control of a rolling load and a rolling tension of a temper rolling mill is performed to control elongation, and a correction amount for compensating an elongation change due to a change in rolling speed is added with a correction amount according to a rolling condition. A method for controlling elongation of a temper rolling mill, comprising feed-forward controlling a rolling load and a rolling tension of the temper rolling mill.