JPS6299495A - Electroplating device for metallic strip - Google Patents

Abstract

PURPOSE:To decrease the loss of electric power without spoiling the quality of a plating surface by providing energizing rolls to opening parts of a plating liquid passage between a revolving roll on which a metallic strip is wound and insoluble electrode so as to seal the opening parts. CONSTITUTION:The insoluble electrode 5 is disposed to face the part of the winding roll 3 where the metallic strip 2 is wound. The plating liquid is passed in the plating liquid passage formed between said roll 3 and the support 4 of the electrode 5 from a supply port 7 toward a discharge port 8 in the arrowmarked running direction of the strip 2 and the flow direction 13 of the counter flow. A potential difference is then given between the above-mentioned electrode 5 and the strip 2 to execute electroplating. The strip energizing rolls 6 are provided to the opening parts 10 in the circumferential direction of the rolls 3 in the above-mentioned plating liquid passage 9 so as to seal said parts in the electroplating device 1 for the metallic strip constituted in the above- mentioned manner.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to an apparatus for electroplating metal strips using a radial plating cell.

<Prior art and its problems> Conventionally, the types of current-carrying rolls in radial plating cells were as follows.

(Form 1) The roll shown in Fig. 6 is an energized roll (Japanese Patent Publication No. 49-2264).

(Form 2) The deflector roll shown in Fig. 7 is an energized roll. (Form 3) An energized roll (contact roll) is pressed against the winding roll shown in Fig. 8.

In these figures, 2 is a metal strip, 3 is a winding roll, 6 is a current-carrying roll, 5 is an electrode, 7 is a plating solution supply port (nozzle), 15 is a hold-down roll, and 16 is a seal roll.

In the type (type 1) in which the winding roll functions as an energizing roll, as shown in FIG. 9, the plating current flows in the thickness direction of the metal strip 2, that is, in the direction shown by arrow 17, so that It has the advantage that the voltage drop due to electrical resistance is small, and therefore the power loss is small. In this method, as shown in FIG. 10, in order to prevent the current-carrying part 61 of the current-carrying roll 6 from being plated, the current-carrying part 61 is limited to the center of the roll body length, and the width of the strip 2 is It is necessary to keep the metal strip 2 in constant contact with the non-current-carrying rubber part 62 outside the current-carrying part from the narrow mountain to the wide width. In this energizing type, since the adhesive properties of the energizing part 61 and the outer rubber part 62 are different, when the metal strip 2 is wound up, a step is formed on the energizing part edge 63 as shown in FIG. May cause scratches on the surface. In addition, the current concentrates on the strip on the rubber part 62, that is, the part of the widthwise end of the strip that is not in contact with the current-carrying part 61, and the strip plating surface of this current concentration part 21 has spots of different quality than other parts. There was a drawback that parts were formed.

In the type (type 2) in which the deflation crawl is a current-carrying roll, as shown in FIG. The voltage drop due to electrical resistance is large, and the power loss is large. Furthermore, the strip temperature increases due to heat generation within the strip. Temperature-dependent alloy plating has the disadvantage that when the slip/rip temperature increases, variations in the plating composition occur or the strip surface dries in spots, impairing the surface appearance.

Winding roll 3 is energized roll (contact roll) 6
As shown in FIG. 8, in the type (type 3) in which the energizing roll 6 and the metal strip 2 are pressed, the current-carrying length within the strip is shortened, so the drawbacks of the type 2 are less. When current flows, the current-carrying roll 6 is electrolytically plated by the plating solution interposed between the two. This sealing plated metal increases over time, creating irregularities on the surface of the current-carrying roll 6 and causing scratches on the metal slip/lip 2 and its surface. Furthermore, when the plating solution exits from the gap between the electrodes, it scatters and adheres to the surface of the metal strip in spots, impairing its appearance.

As explained above, in the conventional electroplating apparatus, even if any of Types 1 to 3 is used, it has not been possible to obtain a plated steel sheet with good plated surface quality.

<Object of the Invention> The present invention solves the above-mentioned drawbacks of the prior art and provides a metal strip electroplating apparatus that can reduce power loss due to the metal strip without impairing the plating surface quality of the metal strip. The purpose is to provide.

<Structure of the invention> Such objects are achieved by the present invention as described below.

That is, the present invention provides plating in the circumferential direction of the rotating roll using a rotating roll around which the metal strip is wound, and a support having an insoluble electrode spaced apart in the radial direction of the rotating roll opposite to the part of the roll where the metal strip is wound. In an electroplating apparatus for a metal strip, which forms a liquid passageway and performs electroplating by flowing a plating liquid through the plating liquid passageway and applying a potential difference between an insoluble electrode and the metal strip, an opening in the circumferential direction of the rotating roll of the plating liquid passageway. The present invention provides a metal strip electroplating apparatus characterized in that a metal strip energized roll is provided to seal the opening.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the metal strip electroplating apparatus of the present invention will be described in detail as shown in the accompanying drawings.

As shown in FIG. 1, in the metal strip electroplating apparatus 1 of the present invention, a continuously running metal strip 2 is wound around a roll 3, and an insoluble electrode 5 is placed on the outside facing the strip 2. Electrode support 4 with
A plating solution passage 9 is formed between the winding roll 3 and the electrode support 4 in the circumferential direction of the winding roll.

The plating solution passage 9 is connected to a plating solution supply lower for supplying the plating solution and a plating solution outlet 8 for discharging the used plating solution. In order to increase the plating current density, it is preferable to employ a so-called counterflow in which the plating solution is jetted in the direction opposite to the running direction of the strip 2. Therefore, it is preferable to install the plating solution supply lower on the outlet side of the strip 2 and the plating solution outlet 8 on the inlet side of the strip 2.

Near the outside of the plating solution supply lower and discharge port 8, there is a plating solution passageway 1 for the strip to enter and exit.
In the present invention, an energizing roll 6.6 is provided so as to seal this opening 10.10, so that the strip 2 is energized and the opening 10.10 is sealed.
10 to prevent the plating solution from spouting out.

In this way, the current-carrying roll 6.6 plays the role of sealing the plating solution at the opening 10.10 at the same time as the current is applied, but there is still a gap between the current-carrying roll 6.6 and the plating liquid supply lower and the discharge port 8. Because of this, the plating solution cannot be completely sealed. Therefore, it is preferable to install a sealing member 11 in this gap to prevent leakage of the plating solution.

Note that, as shown in FIG. 2, since a gap also occurs between the winding roll 3 that forms the plating solution passage 9 and the electrode support 4, the sealing member 12 is fixed to the passage cover 41 of the electrode support 4. The peripheral edges of both sides of the winding roll 3 are side-sealed.

This sealing member 12 was filed by the applicant in 1986-038.
It is preferable to use the interpolar seal member already disclosed in No. 680. That is, this consideration is based on the winding roll 3 of the radial plating layer and the electrode 5 or the channel cover 4 on the electrode 5 side.
1, the interpole sealing member is made of an insulating elastic material, and the winding has a thin part that curves in an arc shape in the longitudinal direction in accordance with the roll;
This is an inter-electrode sealing member characterized in that it has a fixing part that is fixed to the electrode or the channel cover 41 on the electrode side, and the thin part is brought into pressure contact with the roll by hydraulic pressure, and the seal member has a fixing part that is fixed to the electrode or the flow path cover 41 on the electrode side. It has the advantage of low contact surface pressure and low wear.

The sealing members 11 and 12 as described above are preferably made of an insulating elastic material such as rubber, and it is particularly preferable to use a material with excellent wear resistance, such as chloroprene rubber.

The metal strip electroplating apparatus of the present invention can be used for electroplating of various metals and alloys, such as electrogalvanization, tin plating, nickel plating, and zinc alloy plating. Therefore, an appropriate plating solution may be used depending on the type of plating.

Note that the present invention is not limited to the above-mentioned configuration example, and as shown in FIG. It is also possible to provide an outlet 8.8 so that the plating solution supplied from the plating solution supply lower is divided to the left and right, and is discharged from the plating solution outlet 8.8 through the plating solution passage 4 respectively. .

Function> The function of the metal strip electroplating apparatus of the present invention will be briefly explained below.

As shown in FIG. 1, the plating solution enters the plating solution passage 9 from the plating solution supply lower as shown by arrow 13, flows through the plating solution passage 9, and is discharged from the plating solution outlet 8.

The plating solution passage 9 is connected to a sealing member 12 as shown in FIG.
Since the vicinity of the periphery of both sides of the winding roll 3 is sealed, the plating solution does not leak out of the plating solution passage 9 through the gap between the winding roll 3 and the electrode support 4.

In this way, the plating solution supply pressure sent to the plating solution passage 9 needs to be high enough to overcome the flow path resistance. For this purpose, a third
As shown by arrow 14 in the figure, the plating solution is vigorously jetted out of the plating solution passage 9. In order to prevent this, an energized roll 6 that functions as a seal roll is arranged at the front surface of the plating solution supply lower and the rear surface of the plating solution outlet 8, that is, at the opening 10.10 of the plating solution passage. The gap between the discharge port 8 and the energized roll 6 is sealed with a sealing member 11.
By sealing with 11, the openings to and io are sealed, and therefore the plating solution circulates without flowing out of the plating solution passage 9.

The energized roll that functions as a seal roll in this way 6.
6 at the position described above, it becomes possible to minimize the length of current flowing through the metal strip 2, thereby reducing power loss and temperature rise of the metal strip 2. Furthermore, in the present invention, the periphery of the current-carrying roll 6 (=seal roll) is constantly in contact with the supplied plating solution and is wet, so that the metal electrolytically plated on the roll surface at the contact area with the metal strip 2 is removed from the roll. Since it is redissolved by the surrounding plating solution, the amount of adhered plating metal does not increase, and the energized roll 6 always
It is possible to maintain the beautiful surface condition before use.

FIG. 4 shows the results of comparing the surface condition of the current-carrying roll 6, that is, the thickness of Zn deposited on the surface of the current-carrying roll, with that of the current-carrying roll in the conventional plating apparatus shown in FIGS. 7 and 8.

The test conditions were as follows: a sulfuric acid bath zinc plating solution was used, and the amount of current was 2000 A per roll width of 100 mm.

As is clear from the results shown in FIG. 4, the current-carrying roll (seal roll) according to the present invention has almost no plating metal attached to its surface (adhesion thickness 0.05JL+!).
).

<Effects of the Invention> As described above, according to the metal strip electroplating apparatus of the present invention, the plating surface quality of the metal strip is not impaired, and power loss within the chamber can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partial side sectional view of the plating apparatus of the present invention, also showing the flow of plating current. FIG. 2 is a partial front cross-sectional view of the device of the invention showing the side seal between the electrode support and the side of the winding roll. . FIG. 3 is an explanatory diagram showing the spouting state of the plating solution when there is no current-carrying roll (seal roll). FIG. 4 shows the results of comparing the thickness of reliable plating metal (Zn) deposited on the surface of the current-carrying roll in the plating device of the present invention with that of the current-carrying roll in the conventional plating device shown in FIGS. 7 and 8. This is a graph showing. FIG. 5 is a partial side sectional view showing another configuration example of the plating apparatus of the present invention in which the plating solution is flowed into the plating solution passage in a different manner. FIG. 6 is a diagram of a plating cell of the type in which the winding roll is an energized roll. FIG. 7 is a diagram of a plating cell of the type in which the deflector roll is a current-carrying roll. FIG. 288 is a diagram of a plating cell of the type in which a current-carrying roll is pressed against a winding roll. FIG. 9 is an explanatory diagram of the flow of plating current in the cell of the type shown in FIG. 6. FIG. 1O is a perspective view illustrating the relationship between the current-carrying roll (wrapping roll), the strip, and the width of the current-carrying part of the cell of the type shown in FIG. 6. FIG. 11 is a sectional view of the strip contact portion of the energizing roll (winding roll) in the cell of the type shown in FIG. FIG. 12 is an explanatory diagram of the flow of plating current in the cell of the type shown in FIG. 7. Explanation of symbols 1...Metal strip electroplating equipment, 2.
... Strip, 21 ... Current concentration part in the strip, 3 ...
... Winding roll, 4 ... Electrode support, 41 ... Channel cover, 5 ... Electrode, 6 ... Current supply roll, 61 ... ... Current carrying part, 62 ... Non-current carrying part rubber part, 63 ... Current carrying part edge, 7 ... Plating solution supply port, 8 ... Plating Liquid discharge "1. 9...Plating solution passage, lO...Plating solution passage frontage, 11.12...
... Seal member, 13 ... Flow direction of plating solution, 14 ...
・Spouting direction of plating solution, 15...Hold down roll, 16...Seal roll, 17...Longitudinal direction of current FIG, 2 FIG, 4 hours (min)

Claims (1)

[Claims] A method of plating in the circumferential direction of the rotating roll using a rotating roll around which a metal strip is wound, and a support having an insoluble electrode spaced apart in the radial direction of the rotating roll opposite to the part of the roll where the metal strip is wound. In a metal strip electroplating apparatus that forms a liquid passage and performs electroplating by flowing a plating liquid into the plating liquid passage and applying a potential difference between an insoluble electrode and the metal strip, the plating liquid passage has an opening in the circumferential direction of the rotating roll. 1. A metal strip electroplating apparatus, characterized in that a metal strip energized roll is provided to seal the opening.