JPH0318414A - Control device for speed between stands - Google Patents

Abstract

PURPOSE:To control tension within a setting range for tension control for the tension of a material at normal operation even if on malfunction and to restrain the variance of tension on the overall length by selecting and using a loop control device or tension control device according to the object. CONSTITUTION:A material 1 which is bitten in a rolling mill is first controlled with the loop control device 8. And, when the deviation of the output H of a loop detector 7 and setting height Href, of loop is (H-Href=0), the tension T st that time is stored in a memory system 11 for tension and that is taken as Tref. After that, when loop height is within the setting range of loop control, but the tension is beyond the setting range of loop control due to the unusual variation of the tension, 1 is outputted by a setting device 9 for loop control and 0 is outputted by a setting device 13 for tension control. Thereby, tension control is selected by a selection device 14 for loop tension. And, when the tension is within the setting range for control and the loop height is beyond the setting range of control, loop control is selected in the judgement that loop shape is normal, but unbalance is generated in the mass flow of rolling means.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an inter-stand speed control device in a rolling mill.

(Prior art) As shown in Fig. 2, the speed control device in a conventional continuous rolling mill uses a loop position detector 7 installed between the rolling mills to keep the loop height constant, thereby controlling the rolling material. The tension is rarely constant.Also, a control device is known in which the output from the current detector 6 is used for tension control 12 as shown in FIG.

<Problem to be solved by the invention> As described above, in the conventional loop control device, even if the loop height is constant, depending on the shape of the loop, the tension may be large.
Changes to J. For example, in the case shown in FIG. 4, even if the rolling speed is increased to form a loop, the loop height does not change and only the tension increases. In addition, in the case shown in Figure 5, an attempt is made to make the loop smaller, but the kicker 3 prevents the loop from becoming smaller, and only the tension increases, making it impossible to make a normal loop. was difficult.

Further, conventional tension control devices generally have poor control accuracy, and it is difficult to obtain constant dimensions using only this tension control device. For this reason, loop control has been used as much as possible within the range where a loop can be formed.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a rolling mill having a plurality of stands with a loop control device, a material tension control device, and a loop height/material tension control device. The present invention provides an inter-stand speed control device characterized by comprising a selection device for selecting a control method.

(Function) In a device configured in this way, loop control is normally performed, and even in abnormal conditions, the material tension can be controlled within the tension control setting range (±Δ'1゛) compared to the material tension in normal conditions. Fluctuations can be suppressed.

(Example> Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of an inter-stand speed control device according to the present invention.

A rolled material 1 is rolled by a rolling roller 2, and a loop is formed by a kicker 3. A loop detector 7 detects the height of the formed loop, and a loop control device 8 uses this output and a loop height constant Href to control a loop. Control position. The loop control range setting device 9 determines that l(H-Href)l>ΔH based on the deviation (H-Href) between the output H of the loop detector and the loop setting height Href and the loop control setting range Δ}. If so, it outputs 1 and inputs it to the loop/tension selection device 14. The rolling roller 2 is driven by a drive motor 4 that is controlled by a motor control device 5. In addition, the current detector 6 is
The current of the drive motor 4 is detected and output to a tension calculation device 10 that calculates material tension. The tension control device 12 uses the output T of the tension calculation device 10 and the loop H-Href.
Stretch memory device 1 that memorizes the tension cage at =O
The tension is controlled by the output goref with 1. Further, the tension control range setting device 13 determines the deviation (
T-Tref) and the tension control setting range Δ'F.
(T-Tr e f ) 1 > ΔT, 1
is output and input to the loop/tension selection device 14.

As described above, the loop/tension selection device 14 selects a control method based on the output of the loop control range setting device 9 and the output of the tension control range setting device 13.

This selection method will be explained below.

The tension control range setting device i13 determines that when ("I'-Tref) 1 >ΔT,"
1" and continues to output "1" until T-Tref=0. Then, when "I"-T r e f = 0, "0" is output, and l T"-T'r e
It continues to output "0" until f l >Δgo. The control method in such an output method is selected as shown in the table below.

However, after one person controls the material biting, 'T' r e f
[ (I-I-Hre f ) until it is memorized.
10], loop control rONJ, tension control rOF
1? Let it be J.

That is, the material bitten into the rolling mill is first controlled by loop control. Then, when (H-Href)=O, the tension T at that time is stored in the tension memory device 11, and this is 1" r e
Let it be f. After that, the loop height is within the loop control setting range, but if the tension changes abnormally and becomes outside the loop control setting range, that is, IT-Trefl>ΔT, the loop control range setting device 9 is set to "0", and the tension control The range setting device 13 outputs "]." From this, the loop tension selection device selects tension control. (CASEI) Also, if the tension is within the control setting range and the loop height is outside the control setting range, the loop shape is normal, but
Thinking that an imbalance has occurred in the mass flow between rolling mills, loop control is selected.

(CASE2> In addition, if both tension loop heights are outside the control setting range, select tension control, and as a result of performing tension control, CASE
Alternatively, the process moves to CASE 2 and loop control is performed.

[Effects of the Invention] As described in detail above, according to the present invention, by selecting and using the loop control device and the tension control device depending on the purpose, highly accurate and consistent control is possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a loop control device, and FIG. 3 is a block diagram showing a tension control device. 4 and 5 are side views showing an abnormality in the loop shape in the loop 1 control device.

Claims (1)

[Claims] In a rolling mill having a plurality of stands, a loop control device that controls a loop height between the stands, a tension control device that controls a material tension between the stands, and a loop control or tension control based on the loop height and the material tension. An inter-stand speed control device comprising a selection device for selecting.