JPH07166396A - Plating current controller - Google Patents

Abstract

PURPOSE:To control a plating current in such a manner that an optimum plating deposition is assured with a change in plating conditions, such as coating surface density on a strip, strip width, electrode efficiency of electrodes for plating, line speed of a strip line, etc. CONSTITUTION:This plating current controller has a plating deposition detector 12 which detects the plating deposition and central processing units 13, 16 which calculate the correction rate of the plating current for assuring the optimum plating deposition from the value detected by the detector. The plating current is corrected by adding the calculated correction rate of the plating current to an overall current standard (value), by which the optimum plating deposition on the strip 1 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel rolling process line, and when a rolled strip is plated, an optimum plating deposition amount is obtained by controlling a plating deposition amount deposited on the strip by a plating current. The present invention relates to a plating current control device.

[0002]

2. Description of the Related Art A conventional plating current control device performs optimum plating on a strip by controlling the total current (plating current) of a plurality of plating cells for plating the strip. FIG. 6 is a system configuration diagram of a conventional plating current control device. In the figure, 1 is a strip to be plated which travels on the strip line in the M direction (arrow direction in the figure), 2 is a speed detector for detecting the line speed of the strip line of strip 1, 3a-
3c is a plating cell for plating the strip 1 with an electrolytic solution. Reference numerals 4a to 4c are current detectors for detecting the plating current supplied to the plating cells 3a to 3c, and are current transformers (CT), for example. The rectifiers 5a to 5c are composed of switching elements such as thyristors, for example, direct current is controlled by controlling the ignition angle of the switching elements,
Rectifiers 6a to 6c supply the current to the plating cells 3a to 3c as plating currents, and 6a to 6c control the rectifiers 5a to 5c by applying a pulse for controlling the firing angle to switching elements such as thyristors of the rectifiers 5a to 5c. ~ 3
This is a controller that controls the current supplied to c to a predetermined value (set value). 7a to 7c distribute the plating current, and the distributed plating current is distributed to the controllers 6a to 6c.
Distributors 8a and 8b for supplying current to the c are current detectors 4a to 4
It is an adder for obtaining the sum of plating currents from the detection signal of b. For example, the adder 8a adds the currents of the current detectors 4a and 4b. Reference numerals 9a and 9b denote PI controllers that perform feedback control of the plating current based on P (proportional) element and I (integral) element, and output signals to the distributor 7a.
Supply to ~ 7c. 10c and 10d are calculation circuits,
The speed detection value (analog value of current or voltage) obtained from the speed detector 2, that is, the difference between the line speed of the strip 1 and the current reference value is obtained and supplied to the adders 10a and 10b. The adders 10a and 10b find the difference between the sum of the plating currents of the adders 8a and 8b and the outputs of the calculation circuits 10c and 10d, and supply the difference to the PI controllers 9a and 9b. Reference numeral 11 is a current reference circuit that calculates a total current reference (value) from the basis weight of the strip, the plate width, the electrode efficiency of the electrode to be plated, and the line speed, and supplies this value to the calculation circuits 10c and 10d.

Next, the operation of this conventional plating current controller will be described. The plating current supplied to each plating cell 3a-3c is detected by the current detectors 4a-4b,
It is added by the adders 8a and 8b. For example, adder 8
a calculates the sum of the detected values of the current detectors 4a and 4b, and outputs the sum to the adder 10a. Since only the current detector 4c is connected to the adder 8b, the value detected by the current detector 4c is output to the adder 10a. Adder 10
a and 10b obtain the difference between the total sum of the plating currents obtained by the adders 8a and 8b and the total current reference (value) obtained by the calculation circuits 10c and 10d, respectively. It outputs to 9a and 9b. The PI controllers 9a and 9b are adders 10a and 10
The current reference value distributed based on the difference between the total plating current given from b and the total current reference (value) is applied to the distributor 7
a to 7c. The distributors 7a to 7c supply the plating current to the plating cells 3a to 3c via the controllers 6a to 6c, the rectifiers 5a to 5c, and the primary sides of the current detectors 4a to 4c.
Supply to. The line speed of the strip 1 detected by the speed detector 2 is input to the calculation circuits 10c and 10d, and the calculation circuits 10c and 10d are set by the current reference circuit 11 according to the increase or decrease of the line speed of the speed detector 2. Increase or decrease the total current reference (value). That is, for example, when the strip line speed increases, the total current reference (value) is increased.

[0004]

Since the conventional plating current control device is constructed as described above, the plating conditions such as the basis weight of the strip, the plate width, the electrode efficiency of the electrode to be plated and the line speed are changed. In that case, there is a problem that it is difficult to control the plating current by ensuring the optimum amount of deposited plating. That is, the conventional plating current control device calculates the total current reference value by feeding back the line speed to set the current to the plating cell, but it controls in an open loop, and the actual plating adhesion amount. Is not detected. Therefore, there will be a considerable error between the actual deposit on the strip and the set deposit. Therefore, when the plating conditions change, it is difficult to obtain the optimum plating adhesion amount.

The present invention has been made in order to solve the above problems, and even if the plating conditions are changed,
It is an object of the present invention to obtain a plating current control device capable of ensuring an optimum plating adhesion amount.

[0006]

A plating current control apparatus according to the invention of claim 1 detects a deposit amount of plating provided at a predetermined position of the strip line in a strip line of a strip plated by a plating cell. An apparatus and a correction circuit for correcting the plating current by calculating a plating current correction amount for correcting the plating current based on the plating adhesion amount detected by the detection device are provided.

In the plating current control device according to the second aspect of the present invention, the plating current supply system is divided into a front stage side and a rear stage side of the detection device, and the correction circuit corrects the front side supply system. I decided to do it.

In the plating current controller according to the invention of claim 3, the correction circuit corrects the supply system on the rear stage side.

In the plating current control device according to the invention of claim 4, the plating current supply system is divided into a plurality of cells, and the plating current supplied to the plurality of cells of the supply system is divided into a plurality of cells. The correction was made according to the usage load.

[0010]

In the plating current control device according to the present invention, the detection device for detecting the plating adhesion amount is provided at a predetermined position of the strip line. Then, based on the plating adhesion amount detected by this detection device, the correction circuit calculates the plating current correction amount for correcting the plating current, and the total current reference value set by this plating current correction amount is calculated. By correcting, an appropriate amount of plating adhered to the strip is obtained.

In the plating current control device according to the second aspect of the present invention, the system for supplying the plating current to the plating cell is divided into the front stage side and the rear stage side of the detection device. After the division as described above, the correction circuit corrects the supply system on the preceding stage side to obtain an appropriate amount of plating deposition.

In the plating current control device according to the third aspect of the present invention, the correction circuit corrects the plating current of the supply system on the latter stage side to obtain an appropriate amount of deposited plating.

In the plating current controller according to the present invention, the plating current supply system is divided into a plurality of cells and the plating current supplied to the plurality of cells of the supply system is used for each of the plurality of cells. Correct according to the load to obtain a proper amount of plating.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. 1 is a system configuration diagram of a plating current control device showing a first embodiment of the present invention, and FIG. 2 is a flow chart for explaining the operation of the plating current control device of the first embodiment. In this embodiment, the same reference numerals as those in FIG. 6 are used for the parts having the same functions as the above-mentioned conventional example. In FIG. 1, reference numeral 12 is a plating adhesion amount detecting device for detecting the adhesion amount of plating on the strip 1 by using radiation or the like. The strip line of the strip 1 is provided with a plurality of plating cells 3a to 3c arranged in a straight line for plating the strip 1 with an electric current, and the plating adhesion amount detection device 12 is arranged in a straight line. It is provided at a position close to the strip 1 between a plating cell located substantially in the center of the plurality of plating cells and a plating cell adjacent to this plating cell. The detection signal output from the plating adhesion amount detection device 12 is, for example, an analog signal and outputs a voltage value proportional to the plating adhesion amount. Central processing unit 13, 1
Reference numeral 6 denotes a central processing unit that calculates a necessary plating current correction amount (value) by feedforward control from a feedback value from the plating adhesion amount detection device 12 and a feedback value from the stripline speed detector 2.
An A \ D (analog \ digital) converter, for example, is provided on the input side of these central processing units 13 and 16. With this A \ D converter, the analog amount (voltage value) indicating the plating adhesion amount detected by the plating adhesion amount detection device 12 is compared with a reference voltage and converted into a digital value, which is used as the feedback value. Used. Similarly, the speed detection amount from the speed detector 2 is also A \
It is converted into a digital value by the D converter and used as a feedback value. 14 and 17 are calculation circuits 10c and 10d
Is an adder for adding the outputs from the central processing units 13 and 16.

Next, the operation of the apparatus according to the first embodiment will be described. When the plating adhesion amount detection device 12 detects the plating adhesion amount on the strip 1 (step S10), it outputs this detection value as a feedback value to the central processing units 13 and 16. On the other hand, the speed detector 2 detects the speed of the strip line (step S11) and outputs the detected value as a feedback value to the central processing units 13 and 16. The central processing units 13 and 16 calculate a total current reference (value) (step S12), comprehensively judge the amount of plating adhered, the detected value of the line speed, and the set total current reference value to determine the current strip. It is determined whether or not the amount of plating adhered to No. 1 is the optimum one corresponding to the plating conditions (step S13). If the amount of deposited plating is optimum (YES in step S13), the central processing unit 13 does not correct the plating current 1 and supplies the uncorrected plating current to the plating cells 3a to 3c. , Strip 1 is plated. If the amount of deposited plating is not optimal (step S
No in 13), and the correction current value is calculated. That is, the central processing units 13 and 16 calculate the most appropriate feedforward correction current value (plating current correction value) from the feedback value of the speed from the speed detector 2 of the stripline of the amount of plating adhesion (step S14). ).
Then, the calculated value is output to the adders 14 and 17. The adders 14 and 17 add the plating current correction value calculated by the central processing units 13 and 16 to the total current reference (value) of all plating cells output by the calculation circuits 10c and 10d (step S15). Output to the adders 10a and 10b to control the plating current of the plating cell (step S1).
6).

Example 2. Second Embodiment FIG. 3 is a system configuration diagram of a plating current control device showing a second embodiment of the present invention. In the first embodiment, the plating amount detector 12 detects the actual amount of plating, and the central processing unit calculates a plating current correction value from the plating amount. The plating current correction value is used as the plating cells 3a to 3c. The plating current is supplied to the device and all the plating current supply systems are corrected. In the second embodiment, the supply system is divided into a front stage side 30 for supplying a plating current to the plating cells 3a and 3b and a rear stage side for supplying a plating current to the plating cells 3c. Then, only the plating adhesion amount detection device 12, the central processing unit 16 and the adder 17 are provided to correct the plating current supply system on the preceding stage side. That is, the central processing unit 16 is
A feedback value from the plating amount detection device 12,
The plating current correction (value) is calculated from the speed feedback value from the speed detector 2. The adder 17 calculates the plating current correction (value) from the central processing unit 16 by the calculation circuit 10c.
In addition to the total current reference (value) from (1), the corrected current value is output to the calculation circuit 10c to correct the plating current supply system on the front side 30. In this way, according to the second embodiment, the excess or deficiency of the plating adhesion amount detected by the plating adhesion amount detection device 12 is changed by changing the supply system (outputs of the rectifiers 5a and 5b) of the plating current on the preceding stage side. It is possible to compensate for the supply system for the strip 1 at the positions of the plating cells 3a and 3b on the rear side of the plating cell at the inlet of the strip line in the M direction.

Embodiment 3. Fourth Embodiment FIG. 4 is a system configuration diagram of a plating current control device showing a third embodiment of the present invention. In the second embodiment, the system for supplying the plating current is divided into the front stage side and the rear stage side, the plating current correction value is calculated from the speed feedback value of the speed detector 2, and the plating current correction value is used to perform the plating on the front stage side. The current supply system was corrected. In the third embodiment, the plating current correction value is used to correct the plating current supply system on the subsequent stage. That is, the plating adhesion amount detection device 12 and the central processing unit 1
3 and the adder 14 are provided to correct the plating current supply system on the subsequent stage side. That is, the central processing unit 13 calculates the plating current correction value from the feedback value from the plating adhesion amount detection device 12 and the speed feedback value from the speed detector 2. The adder 14 calculates the plating current correction value from the central processing unit 13 by the calculation circuit 10.
In addition to the total current reference (value) from d, the corrected current value is output to the adder 10b to correct the plating current supply system on the rear side 31. In this way, in the second embodiment, the excess or deficiency of the plating deposition amount detected by the plating deposition amount detection device 12 is changed to approximately the center by changing the plating current supply system (output of the rectifier 5c) on the subsequent stage side. It is possible to compensate for the strip 1 at the position of the plating cell 3c on the rear side of the plating cell of No.

Example 4. Fourth Embodiment FIG. 5 is a system configuration diagram of a plating current control device showing a fourth embodiment of the present invention. In addition,
In the first, second or third embodiment, the plating adhesion amount detection device 1
The central processing unit 1 detects the actual amount of plating deposited in 2
In 3 and 16, a correction amount is calculated from the plating adhesion amount, and this correction amount is corrected for all of the plating current supply systems of the plating cells 3a to 3c, the front stage 30 side or the rear stage 31 side. In the fourth embodiment, the load sharing control circuit 15a is used.
15c to PI controllers 9a and 9b and distributor 7a
It was provided between 7c and 7c. By doing this, the PI
By finely adjusting the output signals of the controllers 9a and 9b according to the usage load factor of the plating current, the amount of deposited plating can be controlled more finely. That is, the plating cell 3a
By changing the load factor for each plating current according to the concentration of each plating solution of 3c to 3c, the amount of plating adhered to the strip 1 can be made uniform.

As described above, in the fourth embodiment, the use load sharing control circuits 15a to 15c are provided, and the plating current reference of each plating cell is calculated according to the set value of the use load ratio of the plating current of each plating cell 3a to 3c. I decided to do it. Further, at the same time, a plating adhesion amount detection device 1 for detecting the plating adhesion amount by a feedback signal of the plating adhesion amount 1
Since the total current reference of each plating cell on the rear side of 2 is compensated, the plating current can be set according to the plating conditions such as the concentration of the plating solution, and the weight per unit area of the strip, the plate width, and the electrode to be plated. Even when the plating conditions such as the electrode efficiency and the line speed are changed, it is possible to secure a more optimal amount of the deposited plating. In the above-mentioned fourth embodiment, an example in which the used load sharing control circuit is provided in the plating current supply system on the rear stage side and the correction is made has been described. The same effect can be obtained by providing a use load sharing control circuit in the supply system.

[0020]

According to the first aspect of the present invention, the actual amount of plating adhered to the strip is detected by the detection device, and the correction amount is calculated from the detected value. Therefore, it is optimal even if the plating conditions change. A large amount of plating can be secured.

In the invention according to claim 2, the supply system of the plating current is divided into a front stage side and a rear stage side of the detection device, and the correction circuit corrects the plating current supply system on the front stage side. It is possible to secure a more optimal plating adhesion amount against changes in plating conditions such as the basis weight of the strip, the plate width, the electrode efficiency of the electrode to be plated, and the line speed of the strip.

In the invention according to claim 3, since the correction circuit can correct the plating current supply system on the latter stage side, the basis weight of the strip, the plate width, the electrode efficiency of the electrode to be plated, and the strip line speed. It is possible to secure a more optimal amount of plating adhered to changes in plating conditions such as.

In the invention according to claim 4, the plating current supply system is divided into a plurality of cells, and the plating current supplied to the plurality of cells of the supply system is corrected in accordance with the usage load of each of the plurality of cells. As a result, the plating current can be set according to the plating conditions such as the concentration of the plating solution.
It is possible to secure a more optimal plating adhesion amount against changes in plating conditions such as the basis weight of the strip, the plate width, the electrode efficiency of the electrode to be plated, and the strip line speed.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a plating current control device showing a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of the plating current control device of FIG.

FIG. 3 is a system configuration diagram of a plating current control device showing a second embodiment of the present invention.

FIG. 4 is a system configuration diagram of a plating current control device showing a third embodiment of the present invention.

FIG. 5 is a system configuration diagram of a plating current control device showing a fourth embodiment of the present invention.

FIG. 6 is a system configuration diagram of a conventional plating current control device.

[Explanation of symbols]

 1 strip 2 speed detector 3a-3c plating cell 4a-4b current detector 5a-5c rectifier 6a-6c controller 7a-7c distributor 8a, 8b, 10a, 10b, 14, 17 adder 9a, 9b PI controller 11 current reference Circuit 12 Plating adhesion amount detection device 15a to 15c Working load sharing control circuit 13 and 16 Central processing unit

Claims (4)

[Claims] 1. A plating current supplied to a plurality of plating cells is compared with a current reference value set so as to obtain an optimum plating deposition amount corresponding to a line speed of a strip line to be plated. Based on the comparison result, in the plating current control device for controlling the plating current of each plating cell, the plating adhesion amount detection device provided at a predetermined position of the strip line and the plating adhesion amount detected from this detection device A plating current control device, comprising: a correction circuit for calculating a plating current correction amount for correcting the plating current based on the calculated value to correct the plating current. 2. The plating current supply system is divided into a front stage side and a rear stage side of the detection device, and the correction circuit corrects the supply system on the front stage side. The plating current control device according to item 1. 3. The plating current control device according to claim 2, wherein the correction circuit corrects the supply system on the rear stage side. 4. The plating current supply system is divided into a plurality of cells, and the plating current supplied to the plurality of cells of the supply system is corrected according to the usage load of each of the plurality of cells. 4. The plating current control device according to claim 1, 2 or 3.