JPH01210114A - Catenary control method for steel strip - Google Patents

Abstract

PURPOSE:To stably perform the catenary control regardless of differences of size and sort of the steel strip by performing the speed control of the steel strip to eliminate the reference position of the catenary after correcting based on a steel strip change. CONSTITUTION:As for the catenary control method for the steel strip using a magnetic type steel strip detector on a continuous pickling line, etc., at least two pairs of magnetic type steel strip detectors 3, 6 are used. A 1st group of the steel strip detector 3 is provided on the catenary control position. A 2nd group of the steel strip detector 6 is provided on the constant position of the steel strip bath line usually. The output of the 2nd group steel detector 6 is corrected based on the magnetic property varied by the steel sorts of the steel strip, etc. As the magnetic property of the 2nd group detector 6 differs from the magnetic property of the 1st group detector 3 through the size and steel sort of the steel strip, the output of the detector 6 is corrected through a permeability correcting circuit 7 and a material correcting circuit 8. The corrected output values of the 1st and 2nd groups are fed to a comparator circuit 10 respectively, to compare to obtain a deviation, and based on this deviation, the feeding speed of the steel strip 2 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a catenary control method for steel strip in a continuous pickling line or the like.

(B) Prior Art As a conventional catenary control method for steel strip using a magnetic steel strip detector in a continuous pickling line, etc., as shown in FIG. Catenary position Tr
y is detected by a magnetic steel strip detector 3 provided at the bottom of the pickling tank 1. Each priddle roll 4, 5 provided on the inlet/outlet side of the pickling tank 1 is controlled so as to secure the steel strip 2 at a predetermined catenary position y.

In the conventional catenary control method, the output value of the magnetic steel strip detector 3 corresponds to the steel strip size □y, (width), j
Because it varies (usually 200 degrees) depending on the four types of Ji (components), there are problems as shown in FIGS. 2 and 3.

It is assumed that the steel strip 2A has the characteristics of curve A in FIG. 2, and the catenary position setting in FIG. 3 is yl. Next, when the steel strip 2B having the characteristics of curve B flows through the pickling tank 1, the catenary position setting remains at yI, so the output voltage is controlled to be 1 corresponding to the set value. Therefore, the catenary position moves from y1 to y (FIG. 2). As a result, the catenary position is lowered as shown in Figure 3, and depending on how the catenary position is set, the bottom of the pickling Pa1 may come into contact with the back surface of the steel strip 2B, causing scratches on the back surface with the steel strip. There is.

In addition, in the opposite case to the above, for the steel strip 2C having the characteristic C shown in FIG. 2, the catenary position becomes large as y2 as shown in FIG. The length of immersion becomes long and scale remains. However, we have several tables for each steel strip size (thickness 1 width) and steel type (component) to calculate the curves A, B, C, etc. shown in Figure 2. It is impossible to satisfy all steel strip sizes (thickness, width) and steel types (components) by correcting the material quality on the upper computer to the output value of the steel strip detector 3, and stable catenary control is not possible. .

(c) Problems to be Solved by the Invention The problem to be solved by the present invention is to provide an inexpensive method that can stably control steel strip catenary regardless of the size and type of steel strip.

(d) Means for Solving the Problems The steel strip catenary control method of the present invention includes at least two sets of steel strip catenary control methods using magnetic steel strip detectors in a continuous pickling line, etc. a first set of magnetic steel strip detectors is provided at a catenary control position of the steel strip;
A set of magnetic steel strip detectors is provided at a constant position on a steel strip pass line at all times, an output of the second set of detectors is corrected based on magnetic properties that differ depending on the steel type of the steel strip, etc. The above problem is solved by means consisting of determining a deviation by comparing the output value of the set of detectors with the corrected output value of the second set, and controlling the feed rate of the steel strip based on the deviation. ing.

(E) Embodiment Referring to FIG. 1, the catenary control method for steel strip according to the present invention will be explained. The method of the present invention uses at least two sets of magnetic steel strip detectors 3.6 in a method of controlling the catenary of a steel strip using magnetic steel strip detectors in a continuous pickling line or the like. A first set of magnetic steel strip detectors 3 is provided at a catenary control position of the steel strip (in the illustrated example, at the bottom of the pickling tank 1). Further, a second set of magnetic steel strip detectors 36 is provided at a constant position on the steel strip pass line (in the illustrated example, on the steel strip pass line in the entry side priddle roll 5).

The output of the second set of magnetic steel strip detectors 6 is corrected based on magnetic characteristics that vary depending on the steel type of the steel strip. Second
Since the magnetic properties of the first set of detectors 3 differ depending on the size and steel type of the steel strip, the output of the detectors 6 is applied to the magnetic permeability correction circuit 7 and the material correction circuit 8.
Corrected by.

The corrected output value of the second set of detectors 6 is sent to a comparison circuit 10 via a catenary position setting circuit 9.

The output value of the first set of detectors 3 is also sent to the comparator circuit 10, and compared with the corrected output value of the second set to obtain a +ti difference, and based on this deviation, the feed speed of the steel strip 2 is controlled. .

As shown in FIG. 1, normal steel strip feed rate control uses the same control method for the inlet and outlet pridle rolls 4.5. That is, the motors 41 and 51 that drive the priddle rolls 4.5 compare the set value from the speed setting circuit 12 and the actual value from the speedometer 44.54 directly connected to the motor, and Automatic speed controller 43.
53 and motor drive circuits 42 and 52, the speed is controlled.

In the embodiment of the present invention, the drive speed of the inlet prydle roll 5 is controlled in response to changes in the size and steel type of the steel strip while the drive speed of the outlet prydle roll 4 is maintained constant. . The entrance and exit sides may be reversed. To do this, the output from the comparator circuit 10 is passed through a proportional-integral circuit 11 and sent to the control system of the priddle roll 5 on the input side.

(F) Function In the method of the present invention, as shown in FIG.
When the feed rate of steel strip A is set based on the feed rate of steel strip A, when steel strip A is changed to steel strip B or C, the first set of detectors 3
The output voltage is Va or V for catenary position y8.

Changes to Therefore, after performing the correction ΔVa or ΔVc by changing the steel strip, the speed of the steel strip is controlled so as to eliminate the deviation ΔVl from the catenary reference position y1.

(g) Effects According to the method of the present invention, differences in output voltage due to differences in steel strip size and steel type, i.e., scratches due to contact between the lower part of the pickling tank and the back surface of the steel strip due to lowering of the catenary position, or conversely, It is possible to eliminate quality problems such as scale remaining due to the catenary position rising more than necessary.

Further, when trouble occurs, it is possible to omit cumbersome operations such as changing the catenary distance/output voltage curve by manual intervention and changing the catenary position setting value. In line with this, the accuracy of the catenary position display (display in the operator's cab) has also increased, providing a guideline for operators' operations.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram in which the method of the present invention is applied to a conventional steel strip pickling line. FIG. 2 is a graph showing the relationship between the catenary position and the output voltage of the steel strip detector when the steel strip is changed. Third
The figure is an explanatory diagram of the catenary positions of various steel strips in the pickling tank. 3: 1st set of magnetic steel strip detectors 6: 2nd set of magnetic steel strip detectors (4 other people)

Claims (1)

[Claims] In a method of controlling the catenary of a steel strip using a magnetic steel strip detector in a continuous pickling line, etc., at least two
A first set of magnetic steel strip detectors is provided at a catenary control position of the steel strip, and a second set of magnetic steel strip detectors is installed at a steel strip bus. The output of the second set of detectors is corrected based on the magnetic characteristics that differ depending on the steel type of the steel strip, and the output value of the first set of detectors and the second set of detectors are Comparing with the corrected output value to find the deviation;
A steel strip catenary control method comprising controlling a steel strip feed rate based on the deviation.