JPH0715159B2 - Meandering follow-up control device in electrolytic cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to both end portions in the width direction of a metal strip that runs in an electrolytic bath of an electrolytic treatment line, such as an edge mask installed in the electrolytic bath of an electrolytic plating line. The present invention relates to a meandering follow-up control device for causing a controlled object, which needs to maintain a relative positional relationship with respect to, to follow the meandering in the width direction of a metal strip.

[Conventional technology]

When electrolytically plating metal strips running in the electrolytic cell of the electrolytic plating line with the anodes arranged in parallel facing each other, the plating current concentrates on both ends in the width direction of the metal strips, and Excessive amount of plating adhered at both ends in the direction. In order to prevent this, for example, as shown in FIG. 10, a pair of edge masks 4 are installed in the vicinity of both widthwise end portions of the metal strip 3 traveling in the plating solution 2 in the electrolytic cell 1, and the anode 5 There is known a method of reducing the amount of sticking adhered on both ends in the width direction by cutting off the plating current from the.

On the other hand, when one-sided plating is performed on the metal strip, the plating adheres to the non-plated surface (zero surface) in the vicinity of both ends in the width direction even if the edge mask is used. To remove this, the 11th
As shown in the figure, in the process subsequent to the plating process, the plating solution 7 in the electrolytic bath 6 for reverse electrolysis is filled with the metal strip 8 with one-side plating.
Is known, and a pair of reverse electrolysis cathodes 9 installed on the non-plating surface side near both ends in the width direction of the strip 8 reversely electrolyze both ends of the strip 8 in the non-plating surface width direction. Has been.

By the way, it is important that the edge mask and the reverse electrolysis cathode installed in the electrolytic cell have a constant relative positional relationship with respect to both ends in the width direction of the metal strip, but the metal strip is used when traveling in the electrolytic cell. It may meander in the width direction. For this reason, it becomes necessary to control the position so as to follow the meandering of the metal strip.

There are the following two techniques that have been conventionally used to perform such follow-up position control.

(1) The position of both ends of the metal strip in the width direction is detected outside the electrolytic cell by a pressure-sensitive or optical edge detector, and the edge mask and the reverse electrolysis cathode are moved in the width direction of the metal strip based on the detected position information. , A method of following the meandering of a metal strip.

(2) The DC voltage of the plating solution in contact with the edge mask or the reverse electrolysis cathode is detected and compared with a preset value, and the edge mask and the reverse electrolysis cathode are set in the width direction of the metal strip so that the difference becomes zero. To move to and follow the meandering of metal strips. Regarding the method (2), JP-A-54-128945 is known.

[Problems to be solved by the invention]

However, in the above-mentioned method (1), the positions of both ends of the metal strip in the width direction are detected outside the electrolytic cell, and the position inside the electrolytic cell is estimated based on the detected position outside the electrolytic cell. It ’s just that. For this reason, in the electrolytic cell in which the traveling distance of the metal strip is long, an error occurs in the positions of both ends of the metal strip in the width direction.

The method (2) causes an error due to overvoltage (voltage generated electrochemically) in the detection of the DC voltage of the plating solution,
Operating conditions (plating current value, metal strip size, etc.)
Causes fluctuations and it is difficult to compare with the set value.

From the above, conventionally, it is almost difficult for the edge mask and the reverse electrolytic cathode to follow the meandering of the metal strip, and under the present circumstances, the operator can check the edge mask of the edge mask and the reverse electrolytic cathode while observing the product adhesion state of the product. The reality is that the position is being adjusted.

In view of the above-mentioned present situation, an object of the present invention is to run in an electrolytic bath of an electrolytic treatment line such as an edge mask installed in an electrolytic bath of an electrolysis plating line and a reverse electrolytic cathode installed in an electrolytic bath for reverse electrolysis. The controlled object, which is required to maintain a relative positional relationship with both widthwise ends of the metal strip, can be made to follow the meandering of the metal strip in the widthwise direction, and the width of the metal strip can be changed. It is another object of the present invention to provide a meandering follow-up control device for metal strips in an electrolytic cell that can deal with the above.

[Means for solving problems]

This invention is installed in the vicinity of both widthwise ends of a metal strip traveling in an electrolytic cell and is driven in the widthwise direction of the metal strip.
A pair of controlled bodies, a position detector that detects the position of each of the controlled bodies, and a position control device that controls the position of the controlled body to a set position target value. In a meandering follow-up control device in an electrolytic cell that follows both ends in the width direction of the metal strip, an interval setter that sets an interval between the controlled bodies, a center position in the width direction of the metal strip, and the pair of covered objects. A center position setting device that sets a target value of the difference between the center positions in the width direction of the control body, and a self position and the self position that are installed integrally with the controlled body at the same position of each of the pair of controlled bodies. A pair of distance detectors for detecting a distance in the width direction of the strip between both ends of the strip in the width direction; and a first subtractor for calculating a difference between signals from the position detector of the controlled object. A second calculating a difference between the signals of the pair of distance detectors A subtractor, a third subtractor for calculating a difference between outputs of the first subtractor and the interval setting device, and a fourth subtracter for calculating a difference between outputs of the second subtractor and the center position setting device. And the outputs of the third and fourth subtractors,
Positions of the controlled objects such that the distance between the controlled objects and the difference between the center position in the width direction of the metal strip and the center position in the width direction of the pair of controlled objects are non-interferingly controlled by matrix calculation. It is characterized in that it has a calculator for calculating a command value.

Hereinafter, the meandering tracking control device in the electrolytic cell of the present invention will be described in detail.

FIG. 1 is a configuration diagram showing one embodiment of the meandering tracking control device of the present invention applied to an edge mask installed in an electrolytic cell. In FIG. 1, 10 is a metal strip that travels in the plating solution in the electrolytic cell perpendicularly to the paper surface, 11 is a pair of anodes that are vertically arranged parallel to the metal strip 10, and 12 is a metal strip 10. It is a pair of edge masks installed in the vicinity of both ends in the width direction and driven in the width direction of the metal strip 10. The meandering tracking control device of the present invention is
A pair of edge mask position detectors 13 and a pair of meandering detectors 14
And a controller 15 and a pair of edge mask position controllers 16 basically.

The edge mask position detector 13 comprises, for example, an encoder attached to the servo mobile unit 17 of the edge mask 12.
Each of the position detectors 13 detects a position in the width direction of each metal strip 10 of the edge mask 12, for example, a position based on the center of the electrolytic cell in the width direction. Therefore, the position detector 13
The difference between the position detection values L ₁ and L ₂ obtained by each of the above-mentioned values represents the distance between each of the pair of edge masks 14. The obtained position detection values L ₁ and L ₂ are input to the controller 15.

The meandering detector 14 is a detector developed by the present inventors and recently applied (Japanese Patent Application No. 62-58955). Each of the meandering detectors 14 essentially detects the distance in the width direction between the detection electrode 14a and the widthwise ends of the metal strip 10.
The metal strip 10 is composed of the detection electrode 14a on the side closer to both ends in the width direction and the feed electrode 14b on the far side, and the detection electrode 14a and the feed electrode 14b are fixed to an insulator supporter. , The distance between them is set so that the meandering detectors 14 have the same distance. The pair of meandering detectors 14 are used by applying an alternating voltage from a common alternating current power source 18 between each of the feed electrodes 14b and the metal strip 10.

Now, the metal strips between the respective installation positions of the pair of detection electrodes 14a and the respective widthwise both ends of the metal strip 10 will be described.
If the distances in the width direction of 10 are the same, an AC voltage of the same magnitude corresponding to the distance is generated in each of the detection electrodes 14a. Next, the metal strip 10 meanders in the width direction, for example, to the left side, the distance decreases on the left detection electrode 14a side, and the distance increases on the right detection electrode 14a side, the distance to the left detection electrode 14a increases. The reduced AC voltage is generated according to the decrease, and the increased AC voltage is generated on the right detection electrode 14a according to the increase in the distance. Therefore, the AC voltages V ₁ and V ₂ detected by each of the detection electrodes 14a correspond to the distance in the width direction between each of the detection electrodes 14a and each of the widthwise both ends of the metal strip 10. , Its AC voltage V ₁ , V ₂ (hereinafter distance detection value V
_1, the difference between V ₂ hereinafter) are meandering in the width direction of the center position deviation amount (metal strips between the widthwise center position of the center position and the metal strips 10 between each pair of the detection electrodes 14a amount)
2 times the amount of Therefore, if each pair of detection electrodes 14a is installed at the same position on each edge mask 12, that is, if each pair of meandering detectors 14 is installed, the distance detection values V ₁ , V difference ₂ represents a 2-fold amount of the center position deviation amount between the center position in the width direction of the center position and the metal strips 10 between each of Etsujimasuku 12 pair.

Each of the pair of meandering detectors 14 is installed at the same position of each of the pair of edge masks 12, as described above. Distance detection values V ₁ and V ₂ obtained by each of the pair of meandering detectors 14
Is subjected to AC / DC conversion by the AC / DC converter 19, and then input to the controller 15 like the position detection values L ₁ and L ₂ .

FIG. 2 is a block diagram of a main part of the control system of the meandering tracking control device. As described above, the difference between the position detection values L ₁ and L ₂ obtained by each of the pair of position detectors 13 represents the interval between the pair of edge masks 14, and the pair of meandering detectors 14 The difference between the distance detection values V ₁ and V ₂ obtained by each of the _two is the center position shift amount of the pair of edge masks 14 and the metal strips, which is 2
Represents double dose. Therefore, first, the first subtractor 15a
Therefore, the difference L ₂ -L ₁ between the position detection values L ₁ and L ₂ is calculated by the second subtractor
The difference V ₂ -V ₁ between the distance detection values V ₁ and V ₂ is calculated by 15b to obtain the feed back amount. Then, the third subtractor 15c and the fourth
Of the feedback back amount L ₂ -L ₁ , V ₂ -V ₁
Deviations from the respective set values, namely, the edge mask interval set value L ₀ and the deviation from the center position deviation amount set value V ₀ X ₁ = L _0- (L ₂ -L ₁ ), X ₂ = Take V _0- (V ₂ -V ₁ ). Then, controller 15, to the deviation X ₂ of the deviation X ₁ and the center position deviation amount of the Etsujimasuku intervals, by performing a non-interference by the matrix operation, a position command value Z for each Etsujimasuku 12 pair Calculate ₁ and Z ₂ .

Such decoupling multi-variable processing is performed by the interval between the pair of edge masks 14 and the pair of edge masks 14.
This is for obtaining the position command values Z ₁ and Z ₂ that prevent the central position deviation amounts of the metal strip 10 and the metal strip 10 from becoming mutually disturbing.

Here, Y _1, Y _2, the operation result matrix Q for X _1, X _2, Y ₁
= KX ₁ -X ₂ , Y ₂ = KX ₁ + X ₂ , and Z ₁ , Z ₂ is the result of proportional integration of the integral element (A / s + B) with respect to Y ₁ , Y ₂ , Z ₁ = Y ₁ (A / s +
B) and Z ₂ = Y ₂ (A / s + B). Of these, Y from X ₁ , X _2
The calculation of ₁ and Y ₂ is an essential condition for decoupling, but the calculation of Z ₁ and Z ₂ from Y ₁ and Y ₂ may be selected according to the control characteristics of the controlled object. K is a coefficient for matching the signal from the meandering detector 14 with the unit of the signal from the position detector 13. Position command value obtained by controller 15
Z ₁ and Z ₂ are respectively a pair of edge mask position controllers 16
Is input to one of the two.

When there is no center displacement between the pair of edge masks 12 and the metal strips 10, the pair of meandering detectors 14
Since the difference between the distance detection values V ₁ and V ₂ due to each of the above is zero, the center position deviation amount set value V ₀ is set to zero. Further, metal strips 10 of different widths are continuously threaded in the electrolytic cell, but the edge mask interval setting value L ₀ corresponds to the width of the metal strips 10 threaded in the electrolytic cell based on the threading schedule. Has been set. These center position deviation amount set values V ₀ ,
The edge mask interval set value L ₀ is set by a command from a host computer (not shown) or by an individual interval setter or center position setter.

Each of the pair of edge mask position controllers 16 controls each of the pair of edge masks 12 via the servo mobile unit 17 based on each of the position command values Z ₁ and Z ₂ input from the controller 15. , The widthwise position of the metal strip 10 is adjusted. Thereby, the interval between the pair of edge masks 12 matches the set value L ₀ according to the width of the metal strip 10, and the midpoint of the interval matches the midpoint in the width direction of the metal strip 10. That is, the center position shift amount is the set value V ₀ = 0.
Controlled to match. That is, the pair of edge masks 12 are spaced apart according to the width of the metal strip 10 and move in accordance with the meandering of the metal strip 10 and have a predetermined relative position with respect to both ends in the width direction of the metal strip 10. Keep a relationship.

FIG. 3 shows an overall block diagram of the control system of the above meandering tracking control device. With respect to the gain K ^T of the meandering detector 14, the response T of the edge mask position control system including the edge mask position controller 16 and the servo mover 17, K and B, which are the control constants of the meandering tracking controller, are set to K = 2 / K. ^{When T} and B = AT, the center position shift amount L _C between the pair of edge masks 14 and the metal strips 10
And the edge mask interval L between the pair of edge masks 14
_{W looks} like this:

However, L _P : Center position of the metal strip 10.

In the equation (1), V ₀ is usually zero, and the equation (1) has only the second term. From this, it is understood that the edge mask interval L _W and the center position shift amount L _C are adjusted and controlled with a response of 1 / A (second), respectively. The step response is shown in FIG.

In the above, the case where the edge mask is made to follow the meandering and the width change of the metal strip has been shown, but the tracking control device of the present invention is not limited to the edge mask, and the metal strip traveling in the electrolytic cell such as the reverse electrolytic cathode is used. It is also applicable to the case where the controlled object, which is required to maintain the relative positional relationship with each other, is made to follow the meandering and width change of the metal strip.

〔Example〕

A model-scale electrolytic cell of a single-sided electrogalvanizing line for steel sheets was created, and an edge mask was used to follow the meandering of the steel sheets in the electrolytic cell by applying the present invention.

The prepared electrolytic cell and the moving mechanism of the edge mask incorporated therein are shown in FIG. 5 in a front view and in FIG. 6 in a plan view.
In FIGS. 5 and 6, 20 is an electrolytic cell, 21 is a zinc plating solution,
22 is a steel plate, 23 is an anode, and 24 is an edge mask. Further, 25 is a DC servo motor, 26 is a ball screw, and 27 is a ball nut. One is for supporting the edge mask 24 on the ball nut 27 screwed to the horizontal ball screw 26 via the vertical frame 28, and one end of the ball screw 26 is DC. The movement mechanism of the edge mask 24 is configured by mounting the servo motor 25. 29
Is a potentiometer placed at the other end of the ball screw 26,
The potentiometer 29 detects the position of the edge mask 24 based on the movement amount of the ball screw 26.

The DC servo motor 25 incorporates an edge mask position control system as shown in FIG. In FIG. 7, 30 is an edge mask position controller, 31 is an edge mask moving speed controller,
32 is a DC voltage generator (power transistor unit), 33
Is an edge mask moving speed detector.

Table 1 shows the specifications of major items such as the size of the steel plate 22 and the dimensions of the anode 23.

As shown in FIGS. 8 (A) and 8 (B), the meandering detector 34 installed on the edge mask 24 includes a detecting electrode 34a made of a rod of acid-resistant metal and a feed electrode 34b made of a flat plate, and a steel plate 22. Pair of insulator supporters spaced longitudinally of the
The steel plate 22 was fixed to the steel plate 22 at intervals in the width direction. In FIGS. 8A and 8B, 36 is a fitting hole for mounting the detection electrode 34a provided on the supporter 35, 37 is a screw for mounting the supply electrode 34b to the supporter 35, and 38a and 38b are respectively. Lead wires connected to the detection electrode 34a and the supply electrode 34b.

As shown in FIG. 9, the meandering detector 34 has the detection electrodes 34a on the steel plate 22 side, inside each of the pair of edge masks 24,
It was installed at the deepest place and assembled a detection circuit. In FIG. 9, 39 is a common AC power supply for applying the same AC voltage between each of the pair of feed electrodes 34b and the steel plate 22, and 40 is an AC power supply 39 for the steel plate 22. An insulating transformer for insulation, 41 is a capacitor for cutting DC current sneak into the feed electrode 34b, and 42 is an AC / DC converter. The AC / DC converter detects the distance detection value V detected by each of the pair of detection electrodes 34a.
Converts ₁ , V ₂ (which is an AC voltage) into a DC voltage value.

A microcomputer was used as the controller, and the control system shown in FIG. 2 was constructed.

Under the above-mentioned equipment configuration, the meandering manner of manually swinging in the width direction was performed on the steel plate 22, and the edge mask 24 was controlled to follow this by sample value control. In addition,
The sample time T is 43 msec, the integral constants A = 0.5, B = AT≈
The operation was controlled as 0.

As a result, it was possible to satisfactorily control the gap between the pair of edge masks 24 and the center position deviation between the center position between the edge masks 24 and the center position of the steel plate 22 in the width direction, and both errors were within 1 mm. Also, change the space between the edge masks 24 and the steel plate.
The response delay of the edge mask 24 following the meandering of 22 is
Both could be made as small as 2 seconds.

〔The invention's effect〕

Since the meandering tracking control device of the present invention is configured as described above, it has the following effects.

(1) A controlled object such as an edge mask or a reverse electrolysis cathode, which is required to maintain a relative positional relationship with both widthwise ends of a metal strip traveling in the electrolytic cell, can follow the meandering of the metal strip. At the same time, when the width of the metal strip is changed, it is possible to keep the interval according to the width.

(2) Since the gap between the controlled objects such as the edge mask and the reverse electrolytic cathode and the center position deviation between the metal strip and the metal strip are controlled so as not to interfere with each other, stable control can be performed without causing disturbances.

(3) Since the center displacement between the edge mask and the metal strip is detected by the meandering detector close to the metal strip, the detection accuracy is high, and there is no trouble due to the detection abnormality, and the decoupling control is combined. The control accuracy is 1m
Good as m.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a meandering tracking control device of the present invention, FIG. 2 is a block diagram of a main part of a control system of the control device of FIG. 1, and FIG. Diagram,
FIG. 4 is a step response diagram of the control system shown in FIG.
FIG. 6 is a front view showing the electrolytic cell and the edge mask moving mechanism in the embodiment, FIG. 6 is a plan view of the same, and FIG.
A block diagram showing an edge mask position control system incorporated in the DC servo motor of the moving mechanism of FIGS. 5 and 6, FIG. 8 (A).
Is a front view showing the meandering detector installed in the edge mask of FIG. 5, FIG. 8 (B) is a plan view of the same, and FIG. 9 is a meandering detector of FIG. 8 (A), (B). Fig. 10 is a plan view showing a detection circuit assembled by using Fig. 10, a vertical sectional view showing an electrolytic cell having an edge mask installed, and Fig. 11 is a vertical sectional view showing an electrolytic cell for reverse electrolysis having a reverse electrolytic cathode installed. It is a figure. In the drawing, 10 …… metal strip, 11,23 …… anode, 12,24 ……
Edge mask, 13,30 ... Edge mask position detector, 14,
34: meandering detector, 14a, 34a ... detection electrode, 14b, 34b ...
Feed electrode, 15 ... Control controller, 15a, 15b, 15c, 15d ...
… Subtractor, 16… Edge mask position controller, 17… Servo mobile, 18,39… AC power supply, 19,42… AC / DC converter, 20… Electrolyzer, 21… Zinc plating solution , 22 …… Steel plate, 25 …… DC servo motor, 26 …… Ball screw, 27 ……
Ball nut, 29 ... Potentiometer.

Claims (1)

[Claims] 1. A pair of controlled bodies, which are installed near both widthwise ends of a metal strip traveling in an electrolytic cell and driven in the widthwise direction of the metal strip, and the position of each of the controlled bodies is detected. Which has a position detector for controlling the position of the controlled object to a set position target value, and causes the controlled object to follow the widthwise ends of the metal strip in the electrolytic cell. In a tracking control device, an interval setter for setting an interval between the controlled objects, and a center position for setting a target value of a difference between a central position in the width direction of the metal strip and a central position in the width direction of the pair of controlled objects. A setter and a distance in the width direction of the strip between its own position and both ends in the width direction of the strip, which are integrally installed with the controlled body at the same position in each of the pair of controlled bodies. A pair of distance detectors to detect A first subtractor for calculating a difference between signals from the position detector of the controlled object, a second subtractor for calculating a difference between signals of the pair of distance detectors, and the first subtractor And a third subtractor for calculating the difference between the outputs of the interval setting device, a fourth subtracter for calculating the difference between the outputs of the second subtractor and the center position setting device, and the third subtraction And the output of the fourth subtractor,
Positions of the controlled objects such that the distance between the controlled objects and the difference between the center position in the width direction of the metal strip and the center position in the width direction of the pair of controlled objects are non-interferingly controlled by matrix calculation. A meandering follow-up control device in an electrolytic cell, characterized by having a calculator for calculating a command value.