JPH0148359B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device 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 plating cells.

[Conventional technology]

Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 is the strip to be plated that moves in the direction of the arrow in the figure, 2 is a detector that detects the line speed of strip 1, 3a to 3d are the plating cells that plate the strip 1, and 4a to 4d are the cells supplied to the plating cells 3a to 4d. 5a to 5d are rectifiers that supply the plating current; 6a to 6d are controllers that control the current supplied to the plating cells 3a to 3d via the rectifiers 5a to 5d to a predetermined value; 7a to 5d; 7d is a distributor that distributes the plating current and supplies it to the controllers 6a to 6d; 8 is an adder that calculates the sum of the plating currents from the outputs of the detectors 4a to 4d; and 9 is a PI (proportional, integral) controller with an output The signal is supplied to distributors 7a to 7d. Reference numeral 10 denotes a calculation circuit which increases or decreases a total current reference supplied from a current reference circuit 11 (to be described later) at the line speed of the strip 1 supplied via the detector 2, and supplies the result to the adder 10a. The adder 10a calculates the difference between the total plating current calculated by the adder 8 and the total current reference output from the calculation circuit 10, and supplies the difference to the PI controller 9. 11 is a current reference circuit that sets a comprehensive current standard from plating conditions such as basis weight, board width, and plating electrode efficiency, and supplies this to the calculation circuit 10; 12 is a selection circuit that selects the plating cells 3a to 3d; and 13 is a hysteresis circuit. A circuit 14 is a detection circuit that detects the number of plating cells based on the line speed output from the detector 2 and a pattern of line speed versus plating current density supplied from the calculation circuit 15 described later; 15 is a total current reference from the current reference circuit 11; This is a calculation circuit that calculates the pattern of line speed versus plating current density.

Next, the operation will be explained. Each Metxel 3a
The plating current supplied to detectors 4a to 3d is
d and added by adder 8.
The difference between the sum of the plating currents thus obtained and the total current reference of the calculation circuit 10 is calculated by the adder 10a, and the difference is supplied to the controller 9.
The PI controller 9 sends the distributed total current reference based on the difference given from the adder 10a to the distributor 7.
Supply to a to 7d. The distributors 7a to 7d distribute the plating current to the respective controllers 6a to 6d and the rectifiers 5a to 7d.
Metsuki cell 3 via 5d and rectifiers 4a to 4d.
Supply to a to 3d.

The line speed of the strip 1 detected by the detector 2 is input to the calculation circuit 10, which increases or decreases the total 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 total current reference is increased.

Calculation circuit 15 calculates a pattern of line speed versus plating current density using the overall current reference from current reference circuit 11 and inputs it to detection circuit 14 . The detection circuit 14 detects the number of plating cells based on the line speed supplied from the detector 2 and the pattern of line speed versus plating current density supplied from the calculation circuit 15. The hysteresis circuit 13 is connected to this detection circuit 1.
A selection circuit 12 provides hysteresis to the output of 4.
is the distributor 7 according to the output of the hysteresis circuit 13.
Make a selection from a to 7d.

Figure 2 shows the line speed V detected by the detector 2 and the plating current density D of each plating cell 3a to 3d.
It is a graph showing the selection of Metxel 3a to 3d using the coordinate axis as . Ds indicates the rated current density per Metsuki cell.

Now, line operation is started and line speed V
is the speed L ₁ corresponding to the lower limit value D _L of the plating current density
When it reaches , Metxel 3a is introduced. When the line speed V further increases and reaches the speed U ₁ of the upper limit value D _U , the Metsuki cell 3b is also turned on, the current density D decreases as shown by the mark, and the number of Metsuki cells n
This is shown by the intersection of the =2 patterns. Similarly, if the line speed V continues to increase, the speed
At U ₂ , the number of mesh cells n = 3, and at speed U ₃ , the number of mesh cells n = 4, resulting in the maximum speed V _MAX .

When the line speed V 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 provided by the hysteresis circuit 13 to stabilize the operation, so the trajectory does not match the trajectory when increasing it as shown in the figure.

Since the conventional apparatus is constructed as described above, it has the disadvantage that the plating current density becomes insufficient when the number of plating cells is changed.

[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 the plating current 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. In FIG. _{2 ,} parts with _{the same} symbols as those in FIG _. calculation circuit 1 for calculating L ₄ according to the pattern of line speed versus plating current density supplied from calculation circuit 15;
7 is the shortage interval L′ ₂ calculated by the calculation circuit 16
A setting circuit that sets the line speed (pseudo line speed) used in ~L ₂ , L′ ₃ ~ _{L 3} , and L′ ₄ ~ _{L 4} .
A circuit 10 for calculating this set pseudo line speed
Enter.

Next, the operation will be explained. FIG. 4 is an operational characteristic diagram of the device shown in FIG. 3. When increasing the line speed V to its maximum speed V _MAX , the mesh cell 3a is turned on at a speed L ₁ as shown, and the mesh cell 3b is turned on at a speed U ₁ that is in contact with the rated current density Ds of each mesh cell. As a result, the current density once decreases to L' ₂ and reaches L ₂ to _{U 2} along the pattern of the number of mesh cells n=2. The calculation circuit 16 calculates the plating current shortage interval L' ₂ to L ₂ , and the setting circuit 17 calculates the line speed V in this interval L' ₂ to _{L 2 .}
is set as L ₂ and input to the calculation circuit 10.

Similarly, in the shortage section L' ₃ to L ₃ , the line speed V
is set to L ₃ , and in the shortage section L′ ₄ to L ₄ , the line speed is
Set to _L4 . The calculation circuit 10 compensates the total current reference according to the pseudo line speeds L ₂ , L ₃ , and L ₄ set in this way.

When the line speed V decreases, it is the opposite of the case where the line speed V increases as described above, but as shown in the figure, hysteresis is added when changing the number of mesh cells n due to the action of the hysteresis circuit 13. In Fig. 4, U ₁ = L' ₂ , U ₂ = L' ₃ , U ₃ = L' ₄
It is.

〔Effect of the invention〕

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

[Brief explanation of drawings]

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 switching control device, and is a graph showing the plating current density characteristics of the device shown in FIG. 3. 1 is a strip, 2, 4a to 4d are detectors, 3
a to 3d are metsuki cells, 5a to 5d are rectifiers, 6
a to 6d are controllers, 7a to 7d are distributors,
8, 10a are adders, 9 is PI controller, 1
0, 15, and 16 are calculation circuits, 11 is a current reference circuit, 12 is a selection circuit, and 17 is a setting circuit. In addition, in the figures, the same reference numerals indicate the same parts.

Claims (1)

[Claims] 1 Output from a first adder that calculates the sum of the plating currents supplied to a plurality of plating cells, a current reference circuit that sets the overall current reference from the plating conditions, and a detector that detects the line speed of the strip to be plated. a first calculation circuit that increases or decreases the total current reference from the current reference circuit in response to the current reference circuit; and a mesh current supplied to each of the mesh cells according to the output of the first calculation circuit and the output of the first adder. a second adder for controlling the plating current, a distributor for equally allocating the plating current controlled by the second adder to each of the plating cells, and calculating a pattern of line speed versus plating current density from the overall current reference. a second calculation circuit for determining the number of plating cells from the line speed and the pattern of the line speed versus plating current density; and a selection circuit for selecting the distributor in response to the output of the detection circuit. In the automatic switching control device, a third calculation circuit calculates an area where the plating current density is insufficient when changing the number of plating cells according to the pattern of the line speed versus plating current density, and an output of the third calculation circuit. and a setting circuit that sets a pseudo line speed to be used in the section where the plating current density is insufficient and supplies the pseudo line speed to the first calculation circuit to compensate for the overall current reference. Metsuki current automatic switching control device.