JPH04247898A - Plating current controller - Google Patents

Abstract

PURPOSE:To controll the current density of a plating cell to a specified range. CONSTITUTION:The traveling distance of a strip passing through plating cells 3a-3c is detected by a distance detector 14. According to the detected distance and the referential current, the optimum number of plating cells, timing for acceleration of the line, and timing to switch into the referential plating current are determined by a computing device 15.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating current control device for controlling plating current density during line acceleration so that it falls within a predetermined range.

0002

2. Description of the Related Art FIG. 3 shows a conventional plating current control device, in which numeral 1 indicates a strip to be plated which moves in the direction of the arrow shown, numeral 2 indicates a line speed detector for the strip 1;
3a to 3c are plating cells that plate strip 1;
4a to 4c are current detectors for plating current supplied to plating cells 3a to 3c, 5a to 5c are rectifiers for supplying plating current, and 6a to 6c are currents supplied to plating cells 3a to 3c via rectifiers 5a to 5c. 7a to 7c are distributors that distribute the plating current and supply it to the controllers 6a to 6c, and 8 is an adder for calculating the sum of the plating currents based on the outputs of the current detectors 4a to 4c. 9 is a PI (proportional integral) controller, which supplies output signals to distributors 7a to 7c. 10 is a calculation circuit which calculates the difference between the line speed of the strip 1 obtained through the line speed detector 2 and the current reference, and calculates the difference between the line speed of the strip 1 obtained through the line speed detector 2 and the current reference;
Supply to 0a. The comparator 10a determines the difference between the total plating current obtained by the adder 8 and the output of the calculation circuit 10, and supplies the difference to the PI controller. Reference numeral 11 denotes a current reference circuit that calculates a total current reference from the basis weight, plate width, electrode efficiency, and line speed, and supplies this to the calculation circuit 10.

Next, the operation will be explained. The plating current supplied to each plating cell 3a to 3c is detected by a current detector 4a to
4c and added by adder 8. The difference between the sum of the plating currents thus determined and the total current reference from the calculation circuit 10 is determined in the comparator 10a, and the difference is supplied to the PI controller 9. The PI controller 9 distributes the current reference from the comparator 10a to the distributors 7a to 7c.
supply to. The distributors 7a to 7c distribute the plating current to the respective controllers 6a to 6c, the rectifiers 5a to 5c, and the current detector 4.
It is supplied to the plating cells 3a to 3c via a to 4c. Here, the line speed of the strip 1 detected by the line speed detector 2 is input to the calculation circuit 10, and the calculation circuit 10 calculates the current reference circuit 1 according to the increase or decrease in the line speed.
Increase or decrease the total current reference set by 1. For example, when the line speed increases, the total current reference is increased. By the way, in such a plating current detection device,
During line acceleration, the plating cell total current was solely controlled without strictly controlling the plating current density. The plating current density is calculated from the current value of each plating cell, its electrode length and plate width, and the total current is calculated from the basis weight,
Calculated from plate width, electrode efficiency and line speed. As long as these plating conditions do not change, the total current is controlled to be constant, and the amount of plating deposited is controlled to be constant. However, in the latest plating processes, it has become necessary to control the plating current density within a certain range. This is due to the need for improved gloss of the plated surface, improved electrode efficiency, improved corrosion resistance, etc.

0004

[Problems to be Solved by the Invention] Since the conventional plating current control device is configured as described above, during line acceleration, the calculation circuit 10 performs dynamic control according to the line speed detected by the line speed detector 2. It is necessary to determine the total current of the plating current in order to change the current density of each plating cell 3a to 3c, and there are problems in that it is difficult to control the plating current density within a predetermined range.

The present invention was made to solve the above-mentioned problems, and by determining the optimum acceleration timing and the optimum switching timing of the plating current standard of each plating cell during line acceleration, An object of the present invention is to obtain a plating current control device that controls the current density of each plating cell so that it falls within a predetermined range.

[0006]

[Means for Solving the Problems] A plating current control device according to the present invention detects the advancing distance of a strip passing through a plating cell with a distance detector, and determines the optimum plating cell based on the detected distance and current reference. The number, line acceleration timing, and plating current reference switching timing are determined by an arithmetic unit.

[0007]

[Operation] During line acceleration, the arithmetic device determines the optimal number of plating cells and the optimal timing for line acceleration and plating current reference switching based on the total current according to the target line speed, and thereby determines the current density of each plating cell. compensation so that it falls within a predetermined range.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 12a to 12c are current limiters for keeping the plating current density within a predetermined range; 13 is a speed controller for keeping the speed of the strip 1 constant;
14 is a distance detector that detects the distance traveled by the strip 1, and 15 is an arithmetic unit that determines the optimum acceleration timing and the optimum plating current reference switching timing based on the distance and current reference. Note that other blocks that are the same as those shown in FIG. 3 are given the same reference numerals, and redundant explanation thereof will be omitted.

Further, FIG. 2 is a flowchart showing the plating current control procedure according to the block diagram shown in FIG. In the figure, ST1 is a processing step for determining the optimum number of plating cells, ST2 is a judgment step for increasing the number of plating cells following processing step ST1 for determining the number of plating cells, and ST3 is a step for determining the number of plating cells.
ST4 is a processing step for calculating the optimum timing for switching the plating current reference following the step ST2 for determining the increase in the number of plating cells, ST4 is a processing step for calculating the optimum timing for line acceleration following the plating current reference switching timing calculation step ST3, and ST5 is for calculating the optimum timing for line acceleration following the step ST3 for calculating the plating current reference switching timing. Tracking start processing step following acceleration timing calculation processing step ST4, ST6 is tracking start processing step S
A judgment step for determining whether or not it is an acceleration point following T5, ST7 is a line acceleration processing step following the acceleration point judgment step ST6, ST8 is a judgment step for acceleration completion following the line acceleration processing step ST7, and ST9 is a tracking start processing step. Judgment step of determining whether it is the plating current reference switching point following ST5, ST
10 is a plating current reference switching point judgment step ST9
The plating current reference switching processing step ST11 subsequent to plating current reference switching processing step ST10 is a determination step of completion of plating current reference switching for all plating cells.

Next, the operation will be explained. First, the current reference circuit 11 calculates a comprehensive current reference based on plating conditions, ie, basis weight, board width, electrode efficiency, line speed, etc. Next, the number of plating cells is determined based on this calculated current standard (step ST1), and it is checked whether the number of plating cells increases (step ST2). If the number of cells increases, the plating current standard Calculate the optimal timing for switching (
Step ST3), then the optimum timing for line acceleration is calculated (step ST4). Next, tracking is started (step ST5), and it is determined whether or not it is an acceleration point (step ST6). If it is an acceleration point, line acceleration is performed (step ST7), and processing step ST7 is repeated until the acceleration is completed (step ST8). Otherwise, hold the state until the acceleration point. On the other hand, it is checked whether the plating current reference is a switching point (step ST9), and if it is a switching point,
The plating current reference is switched (step ST10), and processing step ST10 is repeated until the plating current reference switching for all plating cells is completed (step ST11). Otherwise, hold the state until the plating current reference switching point. If the number of cells is not increased in step ST2, which determines whether the number of plating cells is increased, the line is accelerated in step ST7, and step ST7 is repeated until the acceleration is completed in step ST8.

[0011]

As described above, according to the present invention, the traveling distance of the strip passing through the plating cell is detected by the distance detector, and based on the detected distance and the current reference,
Since the optimum number of plating cells, line acceleration timing, and plating current reference switching timing are determined by a calculation device, it is possible to compensate the current density of each plating cell during line acceleration so that it is within a predetermined range. As a result, a certain level of gloss can be obtained, and plating with excellent electrode efficiency and decorative resistance can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a plating current control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a current control procedure by the plating current control device of FIG. 1;

FIG. 3 is a block diagram showing a conventional plating current control device.

[Explanation of symbols]

1 Strip 2 Line speed detector 3a Plating cell 3b Plating cell 3c Plating cell 8 Adder 10a Comparator 14 Distance detector 15 Arithmetic device In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An adder for calculating the sum of plating currents supplied to a plurality of plating cells when the line speed is accelerated; and a line speed detector for detecting the line speed of the strip passing through the plating cells and being plated. , a comparator that compares the sum of the plating currents with a current standard set to obtain a plating current density in a predetermined range corresponding to the line speed, and controls the plating current of the plating cell according to the comparison result. A plating current control device equipped with a distance detector for detecting the advancing distance of the strip, and an optimal number of plating cells, line acceleration timing, and plating current based on the distance detected by the distance detector and a current reference. 1. A plating current control device comprising: a calculation device for determining reference switching timing; and a calculation device for determining reference switching timing.