JPS60128297A - Control device for automatic change-over of plating current - Google Patents

Abstract

PURPOSE:To improve the gloss and corrosion resistance of a plated surface by setting a spurious line speed in the stage of changing the number of plating cells and making current density controllable within a prescribed range. CONSTITUTION:A titled device is provided with the 1st calculation circuit 16, a setting circuit 17 which sets the section where the current density is short by the output from the circuit 16 and the 2nd calculation circuit 10 which compensates current reference according to the setting of the circuit 17 and the line speed of the strip 1. The circuit 16 calculates the section where the plating current density is deficient in the stage of changing the number of plating cells 3a- d according to the prescribed patterns of the line speed versus the plating current density selected by the current reference. The selection of the cells and the plating current are controlled according to the result obtd. by comparing the total sum of the plating current and the current reference set so as to obtain the current density in the prescribed range in accordance with the line speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an apparatus for controlling plating current density within a predetermined range, and particularly for controlling plating current density within a predetermined range even when changing the number of mesh cells.

[Prior art]

Conventionally, there has been a device of this type as shown in FIG.

In the figure, 1 is a strip to be plated that advances in the direction of the arrow shown in the figure, 2 is a detector that detects the line speed of strip 1, 33 to 3d are metsuki cells that plate the strip 1, and 4a to 4d are supplied to metsuki cells 33 to 4d. 5a to 5d are rectifiers K for supplying the plating current; 6a to 6d are controllers for controlling the current supplied to the Menki cells 32 to 3d via the rectifiers 5a to 5d to a predetermined value; 78 ~7d is a distributor that distributes the plating current and supplies it to the control rollers 6a~6d; 8 is an adder that adds the sum of the plating currents to the outputs of the detectors 43~4d; 9 is a PI (proportional, integral) A controller supplies output signals to distributors 7a to 7d. 10 is a calculation circuit which calculates the difference between the line speed of the strip 1 obtained via the detector 2 and the current reference and supplies it to the adder 10a.

The adder 10a calculates the difference between the total plating current of the adder 8 and the output of the calculation circuit 10, and supplies the difference to the PI controller 9. 11 is 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; 12 is a selection circuit that selects the Metx cells 3a to 3d; 13 is a hysteresis circuit; 14 is a detection circuit that detects the rate of increase/decrease in the number of shimetsu cells based on the pulse of the detector 2 and the pattern described below; 15 is a calculation circuit that calculates the pattern of the current density versus the current density based on the current reference from the current reference circuit 11. .

Next, the operation will be explained. The plating currents supplied to each of the mesh cells 3a to 3d are detected by detectors 4a to 4d, and added by an adder 8. The sum of the plating currents thus determined is calculated by an adder 10a as a difference from the total current reference of the calculating circuit 10, and is supplied to the controller 9.

The PI controller 29 supplies the current reference distributed based on the difference provided by the adder 10a to the distributors 73-7d. The distributors 7a to 7d distribute the plating current to each controller 6.
3 to 6d, rectifiers 5a to 5d, and rectifiers 42 to 4d to Metxcells 33 to 3d.

The line speed of the strip 1 detected by the detector 2 is input to the calculation circuit 10, and the calculation circuit 10 increases or decreases the current reference set by the current reference circuit 11 in accordance with the increase or decrease in the line speed.

For example, when the line speed increases, the current reference is increased.

The calculation circuit 15 calculates a pattern of plating current density with respect to line continuity based on the current reference from the current reference circuit 11, and inputs the pattern to the detection circuit 14. The detection circuit 14 detects the line speed of the detector 2 indicating the line speed of the strip 1 and the calculation circuit 1.
Based on the pattern No. 5, the rate of increase/decrease in the number of Metx cells is detected, and the hysteresis circuit 13 applies hysteresis to this rate of increase/decrease. The selection circuit 12 selects the distributors 73 to 7d according to the output of the hysteresis circuit 13.

FIG. 2 is a graph showing the selection of the mesh cells 3a to 3d with the line speed (1) detected by the detector 2 and the plating current density [D] of each of the mesh cells 3a to 3d as coordinate axes. D
s indicates the rated current density per Metsuki cell. The building,
When the line operation is started and the line speed (2) reaches the speed (2), 1 corresponding to the lower limit value DL of the plating current density, the Metsuki cell 3a is introduced. When the line speed ■ further increases and reaches the speed U of the upper limit Du, the Metsuki cell 3b
is also input, the current density decreases as shown by the arrow, and becomes the one shown by the intersection of the ζ turns (with the number of cells n = 2). Similarly, if the line speed ■ continues to increase,
At speed U2, the number of mesh cells n = 3, and at speed U3, the number of mesh cells n = 4, resulting in the maximum speed VMAX.

When the line speed (2) is decreased, it is the opposite of the above-mentioned increase, and the number of mesh cells (n) is sequentially decreased. In this case, when decreasing the number of mesh cells n, hysteresis is applied to the hysteresis circuit 13 to stabilize the operation, so the trajectory when increasing the number n does not match as shown in the figure. Since the structure is as follows, there was a drawback that the current density was insufficient when changing the number of metsuki cells.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is possible to minimize the section where the plating current density is insufficient and to control this within an allowable range. The purpose of the present invention is to provide an automatic switching control device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, parts with the same reference numerals as in FIG.
~L2. L', ~1,3,■,'4~L A calculation circuit that calculates 4 according to Yamao of the calculation circuit 15, 17 is the insufficient interval L'2~L2sL calculated by the calculation circuit 16.
A setting circuit that sets the line speed (pseudo line speed) used in 'S~TJ, , L', ~L4,
This is input to the calculation circuit 10.

Next, the operation will be explained. FIG. 4 is an operational characteristic diagram of the device shown in FIG. 3. line speed ■ its maximum speed VMAX
When increasing the current density to 1, the Metsuki cells 3a are introduced at a speed L1 as shown in the figure, and the rated current density Ds of each Metsuki cell is increased.
Metsuki cell 3b is introduced at U, which is in contact with . As a result, the current density becomes L'.

It follows the pattern of the number of metxoxels n=2 and reaches ~U2. The calculation circuit 16 calculates the plating current shortage interval L/, ~L2 7, and sets the setting circuit 1.
7 is set as L/ in this section, and the line speed is set as - L2, and is input to the subtraction circuit 10.

Similarly, in the insufficient sections L/, ~L, the line speed V is set to , and in the insufficient sections L'4 to L4, the line speed is set to L4.
Set to . The calculation circuit 10 compensates the total current reference according to the line speed, % L3, L4 set in this way.

When the line speed (2) decreases, it is the opposite of the case where the line speed (2) increases as described above, but as shown in the figure, hysteresis is added by the action of the hysteresis circuit 13 when changing the number n of mesh cells. In addition, in FIG. 4, tJ,
=L'2. U,=L', ,U,=L'4.

〔Effect of the invention〕

As described above, according to the present invention, when changing the number of Menki cells, a simulated line speed is set 7 and the plating current density is controlled within a predetermined range, thereby improving the gloss of the plated surface and the corrosion resistance of the plating. It has the effect of improving.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional plating current automatic switching control device, Fig. 2 is a graph showing plating current density characteristics of the device shown in Fig. 1, and Fig. 3 is a plating current automatic switching control device according to an embodiment of the present invention. FIG. 4 is a block diagram of the control device, and is a graph showing plating current density characteristics of the device shown in FIG. 3. 1... Strip, 2, 4a to 4d... Detector, 32
~3d...Metsuki cell, 5a~5d...Rectifier,
68-6d...Controller, 73-7d...Distributor, 8.10a...Adder, 9...Pi controller, 10.15.16...Calculation circuit, 11...
Current reference circuit, 12... selection circuit, 17... setting circuit. Note that in the figures, the same reference numerals indicate the same parts. Agent Masuo Oiwa, Commissioner of the Japan Patent Office 1. Incident display Shijin Isho 58-237713 No. 2,
Name of the invention Plating current automatic switching control device; 3. Person making correction 5, subject of correction

Claims (1)

[Claims] According to the results of comparing the sum of plating currents supplied to multiple Menki cells with the 'rM flow standard, which is set to obtain a plating current density within a predetermined range corresponding to the line speed of the strip being coated, In the plating current automatic switching control device that controls the selection and plating current, the plating current density is calculated in accordance with the predetermined pattern of the line speed versus the plating current density selected based on the current reference, and the section where the plating current density becomes insufficient when the number of Menki cells is changed. 1
a calculation circuit, a setting circuit for setting the section where the shimetsu current density is insufficient due to the output of the first calculation circuit, and a second calculation circuit for compensating the current reference according to the setting of the setting circuit and the line speed. A plating current automatic switching control device characterized by comprising: