JPS6167797A - Automatic selection controlling device of plating cell - Google Patents

Abstract

PURPOSE:To minimize the corrosion and solution of a strip by controlling the increase and decrease of the number of cell by the modification of plating conditions and line speeds in the titled device, which modifies and controls total curr1nt control only. CONSTITUTION:The sum of the current value of each cell 3 is calculated by an adder 8 in the line of plating in a strip 1 through a plural plating cell 3. The line speed is detected by a detector 2 and the current of each cell 3 is controlled from a the speed signal and a total current standard value defined by the current value and the plating condition. A cell selecting circuit 12, sequence pattern circuit 13 using cell, circuit 14 for calculating the number of allowable. unused continuous cell are added to the device. With the changes of plating conditions and line speeds, the increase and decrease of the cell 3 are required, and the continuous number of unused cell in the allowable passing time is calculated from the allowable passing time and the line speeds when the corrosion and solution do not generate in the circuit 14. The optimal used sequence pattern is defined through the circuit 13 to increase and decrease the number of cell in the circuit 12.

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention provides a method for controlling plating current density within a certain range.
The present invention relates to cell loading/disconnection to minimize strip corrosion and dissolution within the plating tank that occurs when controlling the increase/decrease in the number of cells.

(Prior art) In conventional plating current control,
As shown in Figure 1 of No. 60, strict current density control was not performed, and only total current control was performed. In other words, the total current is the basis weight.

It is calculated based on the plate width, electrode efficiency, and line speed, and as long as these plating conditions do not change, the total current is controlled to be constant to keep the amount of plating deposited constant. That is, the increase or decrease in the number of cells is not controlled by changing the line speed.

However, in the latest plating control, in addition to constant control of the plating current, it is also necessary to control the plating current density within a certain range. Therefore, it is necessary to control the increase or decrease in the number of cells as the line speed changes. This plating current saving control and prevention of corrosion/dissolution of the strip improve the gloss of the plating surface, i.
ii. Contributes to improvement of passive rate and corrosion resistance.

Figure 1 shows a conventional plating current control system. (1) is a strip to be plated, (2) is a speed detector, (3) is a metsuki cell, (4) is a plating current detector, (5) is a plating rectifier, (6) is a cell current controller, (7 ) is a plating current divider, (3) is a plating current adder, (9)
is a PI (proportional, integral) controller, 01 is a speed proportional calculation circuit that converts the plating current into a signal proportional to the line speed, and 0η is the total current that calculates the total current standard from the basis weight, board width, electrode efficiency, and line speed. This is a reference calculation circuit.

Plating control is started based on a total current reference value calculated based on a certain plating condition and a line speed corresponding to the total current reference value. The current value of each cell is detected by a plating current detector (4), totaled through a plating current adder (3), and fed back. The difference between the total current reference value that exits the speed proportional calculation circuit 0 and the actual total current value that is fed back is PI.
The plating current is distributed to each cell (3) by a plating current distributor (7) via a (proportional, integral) controller (9). The stain current is controlled by the cell current controller (6) and the plating rectifier (5) based on the current reference distributed across each cell (3).

The total current reference is calculated by a total current reference calculation circuit 0υ based on certain plating conditions, ie, basis weight, board width, i-pole efficiency, and line speed. This total current reference value 0
1) is calculated using the signal from the speed detector (2) when the speed proportional calculation circuit is turned on. That is, as the line speed increases, the current reference value also increases, and as the line speed decreases, the current reference value also decreases.

As described above, in plating current control in which only the total current is changed and controlled as the line speed is changed, the current density of each cell is changed by changing the line speed. The current density is obtained by dividing each cell's current value by each cell's electrode length and board width.

Recent plating control involves increasing or decreasing the number of cells in order to keep the current density within a certain range. If this increase/decrease is simply carried out continuously in the same direction or in the opposite direction to the traveling direction of the strip, several unused cells (cells that are not energized) will be linked together and the passage time of the unused cells of the strip will be lengthened. .

If this passing time exceeds a certain value, there is a problem that corrosion and dissolution of the strip occur. It is an object of the present invention to reduce this corrosion and dissolution.

(Embodiment of the Invention) Fig. 2 shows an example of the case where the present invention is implemented. Fig. 2 shows, in comparison with Fig. 1, the cell usage order pattern circuit 0 of the selection circuit θ, A circuit for calculating the number of continuous cells used has been added.If the plating conditions change, that is, the basis weight, electrode efficiency, plate width, or the line speed changes, the number of cells (3) will need to be increased or decreased. When it becomes necessary to increase or decrease the number of cells (3), the allowable passing time is determined from the allowable passing time without corrosion and melting and the line speed (travel speed of the strip) using the allowable unused continuous cell number calculation circuit a<. Find the consecutive number of unused cells that fall within □. Next, set all the optimal usage order patterns through the cell usage order pattern circuit 0:l. Accordingly, increase or decrease the number of cells with the cell selection circuit Q. Since the permissible passing time differs depending on the type of plating, the control device receives multiple inputs from the outside about the plating type of the strip being run, and the control device makes correspondence between the signals and the permissible time.

〔Effect of the invention〕

As described above, the present invention calculates the allowable number of consecutive unused cells (for example, 1 cell or 2 cells), and then creates N usage order patterns that take into consideration the condition of the cell equipment. By selecting the cells to be used in consideration of acceptable transit times, it is advantageous to provide a control system that can minimize corrosion and dissolution of the strip.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional Metx cell automatic selection control device, and FIG. 2 is a block diagram showing a Metx cell automatic selection control device according to an embodiment of the present invention. (1)...Strip, (2)...Quick detector, (
3)...Metsuki cell, (4)...Plating current detector, (5)...Plating rectifier, (6)...Cell current controller, (7)...Plating current distributor, (8
)...Adder for plating current, 19)...px (proportional.integral) controller, GQ...speed proportional calculation circuit, 0
1)...Total current reference calculation circuit, 0 success...Cell selection circuit, a3...Cell usage order pattern circuit, α→
. . . Permissible unused continuous cell number calculation circuit. In the drawings, the same reference numerals indicate the same parts or the priest parts.

Claims (1)

[Claims] For a plating line that performs plating through multiple plating cells, calculate the sum of the currents flowing through each plating cell, detect the feed speed of the plating line, and calculate the total current set by this speed signal, the current value of the above sum, and the plating conditions. In a plating cell automatic selection control device that controls the current of each plating cell based on a reference value, means for determining the number of unused cells based on information on at least one of the plating conditions and the feed rate, and An automatic plating cell selection control device comprising means for setting a ranking pattern of cells to be used, and plating cell selection means for selecting the plating cells and energizing them based on the means.