JPH09241886A - Method for preventing pressed flaw in electroplated metalllic strip and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of pressed flaws in a metallic strip by forcedly exhausting foreign matter fallen from the electrode face in a vertical electroplating tank to the outside of the metallic strip width. SOLUTION: On the one side, the face on the internally coiled side of a metallic strip 1 in the process of passing between an electrode 5B and sink roll 4A is feedably sprayed (10A) with a plating soln. 15, and foreign matter fallen along the above face is forcedly exhausted to the outside of the metallic strip width. On the other side, the whole area of the surface of the sink roll is provided with a groove 12, and the fallen foreign matter is captured by this groove 12 and is furthermore feedably sprayed (11A) with a plating soln., by which it is forcedly exhausted to the outside of the metallic strip width along the groove.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for preventing flaws on an electroplated metal strip, and more specifically, between a metal strip being processed in a vertical electroplating bath and a sink roll at the bottom of the bath. TECHNICAL FIELD The present invention relates to a method and an apparatus for preventing foreign matter adhering to an electrode surface from falling and being pressed to cause scratches on a metal strip.

[0002]

2. Description of the Related Art A side view of a conventional vertical electroplating equipment generally used for electroplating metal strips is shown in FIG. 3 for tin plating of steel strips. The metal strip (steel strip) 1 is electroplated by being applied with a voltage by the conductor rolls 2A, 2B and the electrodes 5A, 5B while being conveyed in the plating tank 3 filled with the plating solution 15 in the line traveling direction 6.

At this time, foreign matter 8 called sludge accumulates on the inner surfaces of the electrodes 5A and 5B, and the amount of accumulation increases during continuous operation and drops onto the sink roll 4, and is attracted in the direction of rotation 7 to induce the steel strip. There was a problem that the steel strip was bitten between the 1 and the sink roll (flat roll) 4 and a scratch was generated on the steel strip. In order to deal with this problem, conventionally, a net made of steel (not shown) is installed above the sink roll 4 so that the falling foreign matter 8 is captured by the net and does not reach the sink roll 4.

[0004]

However, in the above-mentioned countermeasure, since there is a gap between the metal strip and the net, the foreign matter is not captured completely, and the occurrence of a pressing flaw due to the foreign matter penetrating through the gap is prevented. There was a problem that was impossible. Therefore, the present invention is a method and an apparatus for preventing a flaw on an electroplated metal strip that can prevent the occurrence of a flaw by forcibly discharging foreign matter falling from the electrode surface in a vertical electroplating bath to the outside of the width of the metal strip. The purpose is to provide.

[0005]

According to the method of the present invention, foreign matter adhering to the electrode surface drops and is caught between the metal strip being processed in the vertical electroplating bath and the sink roll at the bottom of the bath. Is a method of preventing the occurrence of push scratches on the inner surface of the metal strip while passing between the electrode and the sink roll, and sprays the plating solution onto the inner winding side surface of the metal strip to drop along the surface. Foreign matter is forcibly discharged to the outside of the width of the metal strip, and on the other hand, a groove is provided on the entire surface of the sink roll to catch the foreign matter that has fallen and to spray the plating solution to forcibly form the metal strip. It is a method for preventing a flaw on an electroplated metal strip, which is characterized in that it is discharged out of the width.

The apparatus of the present invention suitable for the above-mentioned method of the present invention is such that foreign matter adhering to the electrode surface falls between the metal strip being processed in the vertical electroplating tank and the sink roll at the bottom of the tank and is caught in the metal. A device for preventing the occurrence of push scratches on the strip, which is a foreign substance falling along the surface of the metal strip, which is passing between the electrode and the sink roll, by jetting the plating solution onto the inner winding side surface of the strip. Forcibly discharging the gas outside the metal band 1st in line
Spray nozzle, a sink roll that has a groove on the entire surface that catches the foreign matter that has fallen and guides it outside the metal band width, and a plating solution is jetted to the foreign matter that is caught in the groove to force the metal to form a groove. The second spray nozzles arranged in a line to discharge out of the band width, the spray header disposed in the tank for supporting the first and second spray nozzles and distributing the plating solution to these nozzles, and the inside of the tank A device for preventing flaws on an electroplated metal strip, which comprises a pump for feeding a plating solution to a spray header.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is carried out in the following modes. One is to forcibly discharge the foreign matter falling along the inner winding side surface (there are two surfaces) of the metal strip to the outside of the width of the steel plate. For this purpose, for example, a spray header for supporting in a row the first spray nozzles having a spraying direction that faces the inner winding side from below and inclines from the metal band width center to the width end side is provided in the tank. It is preferable that the plating solution in the bath is constantly sent to the spray header by using a pump so as to be supplied from the first spray nozzle. As a result, the foreign matter that is in the process of falling is effectively blown out of the metal band width by the jet pressure of the liquid supply jet from the first spray nozzle.

In addition, instead of the conventional flat roll, the sink roll at the bottom of the vertical electroplating bath is slanted, for example, from the width center portion to both end portions in the direction opposite to the rotation direction of the roll over the entire roll surface. A grooved roll provided with a groove for running is captured by this groove so that foreign matter that has fallen past the liquid jet from the first spray nozzle does not slip down between the metal band and the sink roll. Then, a jet pressure is applied to the captured foreign matter, and the foreign matter is forcibly discharged in a grooved manner outside the metal band.

To this end, for example, it is preferable that the spray header is further provided with second spray nozzles whose injection direction is aligned with the oblique direction of the groove, which are supported in rows. Thereby, the liquid supply can be jetted also from the second spray nozzle, and the foreign matter trapped in the groove is forcibly discharged outside the metal band by the jetting pressure so as not to make a groove. The size (width, depth) of the groove is preferably larger than the size of the foreign matter. However, if there is a size of the foreign matter protruding from the groove, the rolls at both ends (width center and end) of each groove may be rolled. It is desirable that the phase difference in the circumferential direction be less than 90 °. In this way, there is no concern that the foreign matter will reach the contact portion between the metal strip and the sink roll before being pushed into the groove outside the width of the metal strip.

Further, since the mounting positions of the first spray nozzle and the second spray nozzle are apart from each other on the spray header, there is no problem of fitting the mounting positions.
As described above, according to the present invention, the plating liquid is jetted from the first spray nozzle to forcibly discharge the foreign matter on the way to the outside of the metal band width, and the foreign matter that cannot be completely discharged there and is dropped on the sink roll. Is configured to be caught by the groove and forcibly discharge the plating solution from the second spray nozzle to the outside of the metal band so that the foreign matter falling from the inner surface of the electrode will not be absorbed by the sink roll and the metal. It is possible to almost completely prevent the occurrence of push scratches on the surface of the metal strip due to being caught between the strips.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway side view of an embodiment of the device of the present invention, and FIG. 2 is a perspective view of FIG.
It is an arrow side view. In FIGS. 1 and 2, 4A is a sink roll (grooved roll), 9A and 9B are spray headers, 10 is a first spray nozzle, 11 is a second spray nozzle, and 10A and 11A are first and second, respectively. The liquid supplied from the spray nozzle of 12, the groove 12, the pump 13, and the sink roll bearing 14. The same members as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

This embodiment is applied to an electric tin plating line for steel strip. As shown in FIG. 1 and FIG. 2, in the present embodiment, in the portion surrounded by the steel strip 1, the electrode 5B and the sink roll 4, the inner winding side surface of the steel strip 1 and the roll top portion of the sink roll 4 are provided. Spray headers 9A and 9B for jetting the supplied liquid are provided. The spray headers 9A and 9B are provided on the winding side and the unwinding side of the steel strip 1, respectively. The first spray nozzles 10 are attached to each of the spray headers 9A and 9B in a row, and the spray direction is
The surface of the steel strip 1 on the inner winding side is viewed from below and is inclined from the width center toward the left and right width end portions.

A plating solution 15 is fed from one end of each of the spray headers 9A and 9B by a pump 13 from a plating tank 3 and is sprayed as a supply solution 10A from a first spray nozzle 10 onto a surface of an inner winding side of a steel sheet 1. As a result, the foreign matter falling down is blown out of the width of the steel strip 1. Also, Syncroll 4A
Is a grooved roll provided with grooves 12 obliquely running in the direction opposite to the roll rotation direction from the width center portion to the left and right width end portions over the entire surface thereof, and further, spray headers 9A and 9B
2nd, each of which has an injection direction along the oblique direction of the groove 12.
The spray nozzles 11 are attached to one row so that the liquid 11A can be jetted similarly to the first spray nozzle 10. In this embodiment, the size of the groove 12 is set sufficiently larger than the size of foreign matter (about 7 mm).

As a result, the foreign matter that has fallen onto the sink roll 4A is trapped in the groove 12 and carried to the side of the second spray nozzle 11 by the rotation of the roll, and the injection pressure of the supply liquid 11A is directly received, The steel strip is discharged outside the width of the steel strip 1 by the force. It should be noted that the elevation angle of the first spray nozzle 10 is 30 °, the inclination angle is 45 ° evenly on the left and right, and the angle formed by the grooves oblique to the left and right of the grooved roll 4A is 90 °, and the foreign matter that has fallen falls in the roll rotation direction. In the opposite direction, the left and right ends are guided in a direction of 45 °, the direction of the second spray nozzle 11 is set along this direction, and the liquid feed rate of the pump 13 is 0.3 m ³ / min. When this example was applied to an electric tin plating line for a strip, the steel strip, which had conventionally been generated every 15 to 20 times per month, did not occur at all.

The present embodiment discloses the case of electroplating steel strip, but the present invention is not limited to this, and if the vertical electroplating bath is used, the plating source is other than tin. It goes without saying that even if the material to be plated is a metal strip other than steel strip, it can be applied to all such electroplating lines.

[0016]

According to the present invention, it is possible to almost completely prevent foreign matter falling from the inner surface of the electrode in the vertical electroplating tank for a metal strip from being caught between the metal strip and the sink roll during continuous operation. The remarkable effect of effectively preventing the metal band from being flawed can be obtained.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an embodiment of the device of the present invention.

FIG. 2 is a side view taken along the line AA of FIG. 1 including a partially transparent and partially cutaway view.

FIG. 3 is a side view of a conventional vertical electroplating equipment.

[Explanation of symbols]

 1 Metal band (steel band) 2A, 2B Conductor roll 3 Plating tank 4 Sink roll (flat roll) 4A Sink roll (grooved roll) 5A, 5B Electrode 6 Line advancing direction 7 Rotation direction 8 Foreign matter (slurry) 9A, 9B Spray Header 10 First spray nozzle 10A Liquid supplied from first spray nozzle 11 Second spray nozzle 11A Liquid supplied from second spray nozzle 12 Groove 13 Pump 14 Bearing 15 Plating liquid

Claims (2)

[Claims] 1. Preventing foreign matter adhering to the electrode surface from falling between the metal strip being processed in the vertical electroplating bath and the sink roll at the bottom of the bath to be caught and pushed to cause scratches on the metal strip. On the other hand, the plating solution is jetted onto the inner winding side surface of the metal strip that is passing between the electrode and the sink roll, and foreign matter falling along the surface is forced out of the metal strip width. On the other hand, a groove is provided on the entire surface of the sink roll, and the foreign matter that has fallen is trapped by the groove, and the plating solution is jetted as a supply liquid to forcibly discharge it outside the metal band width. A method for preventing flaws on electroplated metal strips. 2. A metal strip being processed in a vertical electroplating bath and a sink roll at the bottom of the bath are prevented from foreign matter adhering to the electrode surface being caught and pressed to cause scratches on the metal strip. Device for spraying the plating solution onto the inner winding side surface of the metal strip that is passing between the electrode and the sink roll to forcibly discharge foreign substances falling along the surface to the outside of the metal strip width. The first spray nozzles arranged in a row, a sink roll having a groove on the entire surface for guiding the fallen foreign matter and guiding it to the outside of the metal band, and a plating solution is sprayed onto the foreign matter captured in the groove. 2 to line up in a row to force the groove to be discharged outside the metal band
Of the spray nozzle, and the first and second disposed in the tank.
An apparatus for preventing flaws on an electroplated metal strip, comprising: a spray header that supports the spray nozzles of 1) and distributes the plating solution to these nozzles; and a pump that sends the plating solution in the bath to the spray header.