JPH0610185A - Electroplating device for metallic strip - Google Patents

Abstract

PURPOSE:To prevent the variation in plating layers and the formation of an edge overcoat by dividing and arranging insoluble electrodes insulated between the electrodes in the transverse direction of a strip. CONSTITUTION:An energizing roll 2 to be wound with the metallic strip 1 is constituted of plural metallic rings 2a to 2k and is constituted by interposing insulators 5a to 5j between the respective rings. Further, the electrodes 3 on the outer side of the strip 1 are constituted by superposing the plural electrodes 3a to 3k divided to a rectangular strip shape in a transverse direction on each other via the insulators 4a, to 4j. The respective rectangular striped electrodes 3a to 3k and the rings 2a to 3k of the power feed roll are respectively so constituted that the on and off of the plating currents from a plating power source 12 can be selected by switches 10, 11. The divided electrodes of a range slightly narrower than the width of the strip are restrictively energized so as not to pass the currents to the outer side or the slight currents of positive and reverse potentials may be passed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a radial type plating cell electroplating apparatus for continuously electroplating metal strips.

[0002]

2. Description of the Related Art Conventionally, as a metal strip electroplating apparatus, there is a radial type plating cell in which a winding roll has a function of an energizing roll in order to reduce a voltage drop due to an electric resistance of the strip and suppress power consumption.

This radial type plating cell divides a curved insoluble electrode, which is installed at a distance in the radial direction of the roll relative to the winding portion of the metal strip of the winding roll, into several pieces in the circumferential direction, and then, in the circumferential direction of the roll. A plating solution passage is formed in the plate, and the plating solution is caused to flow through the plating solution passage and an electric potential is applied between the electrode and the metal strip to perform electroplating.

However, this radial type plating cell is
Since the energizing roll is operated while immersed in the plating solution, the plating metal adheres to the roll part outside the wound strip edge, which increases with time,
The roll surface may have irregularities and scratches on the strip.

In order to prevent the plating metal from adhering to the roll in this radial type plating cell, Japanese Patent Publication No. 49-2
As shown in FIG. 5, in JP H264-264, the current-carrying portion 2α of the current-carrying roll 2 around which the strip 1 is wound is formed only in the central portion of the roll cylinder, and both sides of the current-carrying roll 2 are made non-conductive. It has been proposed to use a roll having a non-energized portion 2β covered with rubber. In this method, the energizing portion 2α of the energizing roll 2 is designed to have a width smaller than the minimum strip width so that the edge of the strip is always located in the non-energizing portion 2β even if the strip width of the strip 1 changes. There is.

On the other hand, as electrodes of the conventional radial type plating cell, there are a soluble electrode type in which the electrode itself elutes to replenish the plating metal ions and an insoluble electrode in which the plating metal ions are replenished from the plating solution. In any case, as shown in FIG. 6, a curved, integral, circumferentially divided electrode 3 having a width equal to or larger than the maximum width of the strip 1 wound around the current-carrying roll 2 has a current-carrying roll. It is arranged at a predetermined interval so as to surround 2.

[0007]

In this conventional radial type plating cell, as shown by the arrow in FIG. 7, the current flow passes through the plating liquid passage 6 supplied from the wide electrode 3 through the header 7. Then, it flows into the narrow strip 1, further passes through the inside of the strip, and then flows from the strip 1 toward the current-carrying portion 2α in the central portion of the current-carrying roll 2.

Therefore, the roll energizing portion 2 of the strip 1 is
The amount of current flowing from the electrode 3 toward the strip 1 is different between the portion in contact with α and the non-energized portion 2β of the roll, and the passing current in the width direction of the strip is different, and the width of the strip 1 is different. Direction, the current density and the strip temperature vary in the plate width direction, and the amount and quality of plating adhered to the strip surface vary in the plate width direction. Moreover, since the electrode 3 is formed wider than the width of the strip 1,
Current tends to concentrate at the end of the strip 1, so
There is a drawback that an edge overcoat of plating occurs.

As a measure against this, Japanese Patent Laid-Open No. 63-83295
It is also proposed to provide a protection means such as an edge mask device as disclosed in Japanese Patent Publication, but since the edge mask is installed in the gap between the narrow electrode and the roll in the vicinity of the edge of the plate, it is necessary when the plate is passed. The meandering of the plate causes the plate and the edge mask to come into contact with each other, resulting in an accident that damages the edge mask, and the function of moving the edge mask in the plate width direction according to the plate width and meandering is due to the adhesion of solid matter in the plating solution. It may cause a defect. Therefore, downtime and maintenance frequency are significantly increased, which is not preferable.

An object of the present invention is to provide an electroplating apparatus for a metal strip which does not cause variations in the plating layer in the width direction of the plating surface of the strip surface and formation of an edge overcoat, and further reduces maintenance frequency and downtime. Especially.

[0011]

According to the present invention, a plating solution passage is formed between a metal strip and an insoluble electrode that is installed opposite to the metal strip, and the plating solution is flowed through the plating solution passage. In a metal strip electroplating device for electroplating by applying an electric potential between an insoluble electrode and a metal strip, the insoluble electrode is divided in the strip width direction, and the divided electrodes are electrically insulated from each other,
Moreover, it is characterized in that electrical connection and disconnection to each electrode is enabled.

Further, a rotating roll around which the metal strip is wound and an insoluble electrode provided at a distance in the radial direction of the roll relative to the wound portion of the metal strip of the roll form a plating solution passage in the circumferential direction of the roll, By applying the plating solution to the plating solution passage and applying an electric potential between the insoluble electrode and the metal strip to apply the electroplating apparatus for the metal strip to perform the electroplating, the rotary roll is formed from a plurality of rings, and Allowing electrical connection to the ring, dividing the insoluble electrode in the width direction of the metal strip, and electrically insulating between the divided electrodes to allow electrical connection to each electrode One or both of the above are adopted.

[0013]

By making the split electrode or the split portion of the rotating roll electrically discontinuous, the width of the current flowing between the metal strip and the electrode can be adjusted to be approximately the same as the width of the metal strip passing through. This makes it possible to make the amount of current flowing from the electrode toward the metal strip and the passing current uniform in the width direction of the metal strip.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The attached FIGS. 1 to 4 show an embodiment of the present invention. An example in which the present invention is applied to a radial type plating cell electroplating apparatus will be described.

FIG. 1 shows a radial type plating cell.
1 shows a structure of an energizing roll 2 around which a metal strip 1 is wound, and the energizing roll 2 includes a plurality of metal rings 2a to 2k.
And insulators 5a-5 between each ring.
The structure is divided into a plurality of parts in the strip width direction with j interposed.

FIG. 2 shows the electrode structure of the radial type plating cell of this embodiment. The electrode 3 is composed of a plurality of electrodes 3a to 3k divided into strips in the width direction of the strip 1 and an insulator 4.
The strip-shaped electrodes 3a to 3k are electrically separated from each other by being overlapped with each other via a to 4j.

Further, FIG. 3 shows the energizing roll 2 shown in FIG.
2 is a diagram showing a radial type electroplating apparatus configured by combining the electrode 3 shown in FIG. 2 and the electrode 3 shown in FIG. A plating solution passage 6 is formed in the circumferential direction of the roll by electrodes 3 divided into several pieces in a curved circumferential direction, which are installed at a distance in the radial direction of the roll, facing the winding portion of the energizing roll 2 and the metal strip 1. Then, the plating solution is caused to flow through the plating solution passage 6 and a potential is applied between the electrode 3 and the metal strip 1 to perform electroplating.

FIG. 4 shows an electric circuit of this plating cell. Each strip electrode 3a to 3k and each ring 2a to 2k of the power supply roll are arranged in the width direction according to the width of the strip. Through the plating power supply 12
Therefore, it is possible to interrupt the plating current from the strip 1 and form an optimum energization width without causing an edge overcoat on the strip 1 to be threaded.

Since the radial type plating cell to which the present invention is applied has the above-mentioned structure, when plating a strip having a certain width, as shown in FIG. 4, the strip-shaped electrode of a portion narrower than the strip width is used. 3d to 3h, and a ring 2d to form the power feeding roll 2 in a portion narrower than the strip width.
Pass current only for 2h.

The strip electrodes 3a to 3c and 3i to 3k, which are wider than the strip width, and the rings 2a to 2c and the rings 2i to 2k, which form the energizing roll 2, are shut off from the current.

As a result, the plating current flows from the divided electrodes 3d to 3h, which are slightly narrower than the strip width, through the plating liquid passage 6 to the strip 1 slightly wider than the electrodes, and further passes through the inside of the strip to reach the strip. It flows toward the rings 2d to 2h of the energizing roll 2 which is narrower than the above.

Further, only the metal rings 2d to 2h of the current-carrying roll 2 on which the strip 1 is wound are limited as the current-carrying part, and no electric current is applied to the portion of the roll cylinder outside the strip edge, or the forward and reverse potentials are applied. A weak electric current is applied. In addition, the edge portion of the strip is designed so as to be wound around the non-conducting insulating ring portion. The amount of current and polarity outside the strip edge is controlled by the adhesion of the plated metal to the roll and the amount of wear due to the elution of roll components.

The example in which the present invention is applied to the radial type plating cell has been described above. However, it is possible to apply only the strip electrode of the present invention to a normal horizontal type plating cell or a vertical type plating cell.

[0024]

The present invention has the following effects.

(1) The amount of current flowing from the electrode to the strip and the passing current can be made uniform in the strip width direction by making the range of current flow from the electrode to the energizing roll substantially the same in the strip width direction. It will be possible. As a result, it is possible to prevent variations in current density and strip temperature in the strip width direction in the strip width direction, and to make the amount and quality of plating adhered to the strip surface uniform in the strip width direction.

(2) Further, by adjusting the current amount of each electrode individually, the current density can be adjusted with higher precision, and the amount of plating adhered to the strip surface and the uniformity of the quality in the plate width direction are significantly improved. it can.

(3) Further, since the electrode width can be set narrower than the strip width, it is possible to reduce the current amount at the end portion of the strip. As a result, it is possible to prevent current concentration at the strip edge portion and prevent edge overcoating of plating. This results in high downtime,
No need to install an edge mask device that requires high-frequency maintenance.

(4) By limiting only the ring-shaped current-carrying roll to the current-carrying part and adjusting the current at the portion outside the strip edge of the roll cylinder, the ring of the winding roll outside the strip edge is coated with plated metal. Adhesion can be prevented.

[Brief description of drawings]

FIG. 1 shows an example of a winding roll of a radial type plating cell of the present invention.

FIG. 2 shows an embodiment in which the electrode structure of the present invention is applied to an electrode of a radial type plating cell.

FIG. 3 shows a configuration diagram in which an electrode and a winding roll of the radial type plating cell of the present invention are combined.

FIG. 4 shows an electric circuit of the plating cell of the present invention.

FIG. 5 shows a conventional example in which a winding roll is an energizing roll.

FIG. 6 shows a structure of a conventional radial type plating cell.

FIG. 7 shows a current flow when plating a conventional radial type plating cell.

[Explanation of symbols]

1: Metal strip 2: Energizing roll 2α: Roll energizing part 2β: Non-energizing part 2a to 2k: Metal ring 3: Electrode 3a to 3k: Strip-shaped electrode 4: Insulator for electrode 5: Ring-shaped insulator 6: Plating solution Passage 7: Liquid supply header 8: Current flow 9: Bus bar 10: Switch 11: Switch 12: Plating power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C25D 21/00 G 21/12 M

Claims (3)

[Claims] 1. A plating solution passage is formed between a metal strip and an insoluble electrode which is installed opposite to the metal strip, and a plating solution is caused to flow through the plating solution passage and at the same time, between the insoluble electrode and the metal strip. In a metal strip electroplating apparatus for applying an electric potential to perform electroplating, the insoluble electrode is divided in the strip width direction, an insulator is interposed between the divided electrodes, and electrical connection to each divided electrode is performed. A metal strip electroplating device that enables 2. A plating solution passage is formed in the circumferential direction of the roll by a rotating roll around which the metal strip is wound and an insoluble electrode which is installed at a distance in the radial direction of the roll in relation to the wound portion of the metal strip. In a metal strip electroplating device for performing electroplating by supplying a potential between an insoluble electrode and a metal strip while flowing a plating liquid in a plating liquid passage, the rotating roll is formed by a plurality of metal rings and between each ring. An electroplating device for metal strips that allows electrical connection and disconnection to each ring through an insulator. 3. A plating solution passage is formed in the circumferential direction of the roll by a rotating roll around which the metal strip is wound and an insoluble electrode which is installed at a distance in the radial direction of the roll relative to the wound portion of the metal strip. In a metal strip electroplating apparatus for performing electroplating by supplying a potential between the insoluble electrode and the metal strip while flowing the plating solution in the plating liquid passage, the insoluble electrode is divided in the strip width direction, and An insulating material is interposed between the electrodes to enable electrical connection and disconnection to each divided electrode, and the rotating roll is formed of a plurality of metal rings, and an insulating material is interposed between the rings to electrically connect to each ring. Electroplating device for metal strips that enables periodic interruptions.