JPS61296921A - Shape straightening method for strip - Google Patents

Abstract

PURPOSE:To perform shape straightening stably at all times by detecting a strip shape on the inlet side of an inlet side bridle and on the outlet side of an outlet side bridle and controlling an elongation percentage of a leveling mill and of a strip based on the detected value. CONSTITUTION:Every detected signal from an evenness detector 35a, C warp detector 36a, L warp detector 37a, auricular wave detector 38a, and medium wave detector 39a set on the inlet side of an inlet side bridle 3 is inputted into an arithmetic processing unit 40. Detected signals from an evenness detector 35, C warp detector 38, and medium wave detector 39 are also inputted into the processing unit 40. The processing unit 40 performs arithmetic processing of those signals and controls servo-valves 27-30, a motor for a roll shifting device, and a stretching motor 23 based on the outputted signal. In this way, an inter mesh of the leveling mill 2, shift quantity of shift rolls 9 and 10, and an elongation percentage of the strip 1 are adjusted. That shape control makes strip products high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in the shape straightening method of a rolled strip material (hereinafter referred to as a strip) such as a cooled steel plate in a tension leveler.

<Prior art> Rolled strips usually suffer from partial elongation such as ear waves, medium waves, L warping, etc. due to uneven temperature distribution during the manufacturing process, lack of mechanical precision of equipment, poor adjustment, etc. It has a shape defect due to bending such as C warpage. Such shape defects not only impair the appearance of the sheet product and reduce its commercial value, but also reduce the threading efficiency during the strip processing process, impede automation, and create new distortions in the secondary processing of the strip. In addition to problems such as generation of scratches, demands for improving the shape quality of strips have become increasingly strict in recent years.

In order to meet such demands, the present applicant previously proposed a method for correcting the shape of a strip using a tension leveler as disclosed in Japanese Patent Application No. 138980/1980.

That is, the outline of the present straightening method is as shown in the schematic configuration diagram of a tension leveler in Fig. 2, in which the strip 1 under tension is repeatedly bent to cause permanent elongation to correct the shape. Leveling mill 2 and
It has a pair of bridles 3.4 installed at the input and output sides of the leveling mill, and means for applying tension to the strip 1 by applying a predetermined elongation rate to the strip 1 by the speed difference between the bridles. In the tension leveler, the actual shape of the strip 1 after shape correction on the exit side of the exit side bridle 4, that is, flatness, 1 warpage,
Shape detectors 35, 38, 37. detect ear waves and medium waves, respectively.
38 and 39, and feed back to the leveling mill 2 and bridles 3 and 4 based on the detection signal, and correct the shape of the strip by controlling the leveling mill's intermesh and roll shift amount and the elongation rate of the strip 1. This is what we intend to do.

In the figure, 5 to 8 are work rolls, 5a and 8a are backup rolls, 7a and 8a are deflector rolls, and 9°1
0 is the shift roll, 17 is the main motor, 18a, 1
8b is a bevel gear, 19a and 19b are pinion stands, 21 is a planetary gear system, 23 is a stretching motor, 27 to 30 are servo valves, and 31 to 34 are hydraulic cylinders.

35 is a flatness detector, 36 is a C warp detector, 37 is an L warp detector, 38 is an ear wave detector, 39 is a medium wave detector, and 4° is an arithmetic processing unit.

However, in the shape correction method described above, since the shape of the strip 1 whose shape has already been corrected by the leveling mill 2 is detected, the detected shape error, that is, the detected amount is extremely small, and therefore, this detected value is expanded. And a leveling mill? And bridle 3.4 will be ivy. Therefore, depending on the specification conditions of the strip, an excessively excessive tension and intermeshed may be applied to the strip 1 than necessary, which causes a problem in that the internal quality of the strip is adversely affected.

Furthermore, in such a tension leveler, the overall line length is short as the strip 1 passing speed is high (for example, in the case of the illustrated device, the line speed is about 1.000 m/mm and the line length is about 10 m), so the exit side In the straightening method that feeds back the strip shape on the exit side of the bridle 4, a straightening error occurs due to a time delay in the control system, and it is difficult to stably form a strip with a desired highly accurate shape (for example, a steepness of 0.2% or less). It is difficult to produce, and further improvements are strongly required.

(Problems to be Solved by the Invention) The present invention has been proposed in view of the above-mentioned problems, and it constantly performs stable and highly accurate shape correction without impairing the internal quality of the strip, thereby achieving high quality. The purpose of the present invention is to propose a method for straightening strips that can obtain a strip product of 100%.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a leveling mill that corrects the shape by repeatedly bending the strip under tension to cause permanent elongation. and a tensioner comprising a pair of bridles installed at the input and output sides of the leveling mill, and means for applying tension to the strip by applying a predetermined elongation rate to the strip by a speed difference between the bridles. In the leveler, the elongation rate of the input bridle is given to detect the shape of the strip and the shape of the strip on the exit side of the exit bridle, and based on these detection signals, the intermesh of the leveling mill and the strip A method for correcting the shape of a strip, characterized in that the shape is corrected by controlling the elongation rate of the strip.

<Function> The shape of the strip detected on the inlet side of the tension leveler is fed forward to the leveling mill and the inlet and outlet bridles, and the shape of the strip detected on the outlet side of the tension leveler is fed forward to the leveling mill and the inlet bridle. , and is fed back to the exit bridle to correct the shape of the strip while correcting the set interface, roll shift amount, and elongation rate.

<Examples> Hereinafter, the present invention will be explained in detail based on examples shown in the drawings. FIG. 1 is a schematic configuration diagram of a tension leveler according to an embodiment of the present invention, and the same or similar members as those in the conventional device (FIG. 2) are given the same reference numerals and redundant explanations will be omitted. .

As shown in FIG. 1, near the entrance side of the entrance bridle 3, a flatness detector 35a,
C warp detector 3Q, L warp detector 37a, ear wave detector 3
8a, a shape detector of the strip 1 such as a medium wave detector 39a is installed, and these detect the flatness of the strip 1 and the amount of elongation of the warp part 5 by giving the tension leveler elongation rate, and also detect the detection signals of the strip 1. is input to the arithmetic processing unit 40. Similarly, detection signals from shape detectors of the strip 1, such as a flatness detector 35, a C warp detector 38, and a medium wave detector 39, installed on the exit side of the exit bridle 4 are input to the arithmetic processing device 40. . The arithmetic processing unit 40 performs arithmetic processing on the detection signals of the shape detectors 35 to 39 and 35a to 39a, and based on the output signals, the servo valve 2
7 to 30, the motor of the roll shift device (not shown) and the stretching motor 23 are controlled respectively to control the intermeshes of the leveling mill 2, the shift amount of the shift rolls 9 and 10, and the elongation rate of the strip 1; There is.

With the above configuration, in order to correct the shape of the strip 1, first, a leveling mill is used according to the specification conditions of the strip 1 (width, thickness, proof stress or yield point stress, amount of ear waves and medium waves). 2 each interface, shift roll 9.
After setting the shift amount of 10 and the elongation rate of the strip 1, the strip 1 is passed through the leveling mill 2. After that,
The actual flatness of the strip l before and after shape correction 1 warp, ear wave and medium wave are detected by shape detectors 35a to 39a and 35.
- 39, and feed forward and feedback them to the leveling mill 2 and bridle 3.4 to correct the shape of the strip 1 while correcting the set interface, roll shift amount, and elongation rate.

<Effects of the Invention> As specifically explained above, in the present invention, the elongation rate of the tension leveler is given, the shape of the strip is detected, and the shape is fed forward to the leveling mill and the inlet and outlet bridles. At the same time, in order to correct the shape of the strip while detecting the shape of the strip on the exit side of the tension leveler and feeding it back to the leveling mill and the input and exit bridles to correct the set interface, roll shift amount and elongation rate, Unlike conventional straightening methods, it is possible to accurately correct the shape by following the strip threading speed without applying excessive tension to the strip, so it is possible to constantly follow various fluctuations in the strip. In addition, it is possible to perform stable and highly accurate shape correction, and it is possible to provide strip products of higher quality.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a tension leveler according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional tension leveler. In the drawing, 1 is the strip, 2 is the leveling mill, 3 is the entry bridle, 4 is the exit bridle, 35° 35
a is a flatness detector, 3B, 38a is a C warp detector, 37.37a is an L warp detector, 38.38a is an ear wave detector, 39.39a is a medium-wave detector, 40 is an arithmetic processing unit It is.

Claims (1)

[Claims] A leveling mill that corrects the shape by repeatedly bending a strip under tension to cause permanent elongation; a pair of bridles installed at the input and output sides of the leveling mill; In the tension leveler, the shape of the strip on the entry side of the entry bridle and the shape of the strip on the exit side of the exit bridle are determined. A method for correcting the shape of a strip, characterized in that the shape is corrected by detecting the shape and controlling the intermesh of the leveling mill and the elongation rate of the strip based on the detection signals.