JPH06256991A - Continuous electroplating device for steel strip - Google Patents

Abstract

PURPOSE:To form electroplating layers having excellent quality on the surfaces of a steel strip with the continuous electroplating device for continuously forming the electroplating layers on the surfaces of the steel strip by uniformaizing the flow velocity distribution of a plating liquid in the transverse direction of the steel strip without generating a disturbance in the flow of the plating liquid ejecting from plating liquid ejection nozzles. CONSTITUTION:This electroplating device is provided with the nozzles 7 for passing the plating liquid in the spacings between the steel strip 3 and electrode plates 2 in proximity to the steel strip outlet side ends of the electrode plates 2 placed on both sides of the steel strip 3 under movement in a plating cell 1 while holding the strip in-between. The device is provided with nozzles 8 for sucking the plating liquid in proximity to the steel strip inlet side ends of the electrode plates 2. The plating liquid discharged from the inlet side ends is sucked by these nozzles 8 for suction, by which the flow velocity distribution of the plating liquid is uniformized in the transverse direction of the steel strip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous electroplating apparatus for steel strip for continuously forming an electroplating layer on the surface of steel strip.

[0002]

2. Description of the Related Art Electroplating of steel strip is generally performed by a horizontal continuous electroplating apparatus or a vertical continuous electroplating apparatus. The horizontal continuous electroplating apparatus is shown in FIG. 10 in a schematic vertical sectional view and in FIG. 11 in a schematic plan view, in which a horizontal electroplating bath 1 for containing an electroplating solution 4 and an electroplating bath 1 are provided. And a pair of electrode plates 2 and 2 arranged substantially in parallel with the steel strip 3 which is moving horizontally, with the steel strip 3 interposed therebetween and with a predetermined gap above and below the steel strip 3, and an electroplating bath 1. A pair of inlet side guide rolls 5 and 5 for guiding the steel strip 3 provided on the inlet side of the steel strip 3 and the steel strip 3 on the outlet side of the electroplating tank 1. It was sandwiched between
A pair of exit guide rolls for guiding the steel strip 3.
6,6 and a pair of electrode plates 2,2 at the steel strip exit side end, which are arranged toward the gap between the steel strip 3 and each of the pair of electrode plates 2,2, It comprises nozzles 7, 7 for jetting a plating solution for flowing an electroplating solution in the direction opposite to the moving direction of the steel strip 3.

The electroplating solution is ejected from the plating solution ejection nozzles 7, 7 toward the gap between the steel strip 3 and each of the pair of electrode plates 2, 2. The jetted electroplating solution flows in the gap in the direction opposite to the moving direction of the steel strip 3, and is discharged from the steel strip entry side ends of the electrode plates 2, 2. Between the electrode plates 2,2 and the moving steel strip 3,
An electric current is passed through the electroplating solution 4. Thus, electroplating layers are formed on both surfaces of the steel strip 3.

When the electroplating layer is formed on the surface of the steel strip 3 by the above-mentioned apparatus, the plating solution is jetted from the nozzles 7, 7 and between each of the electrode plates 2, 2 and the steel strip 3. The flow rate of the electroplating solution 4 flowing in the direction opposite to the moving direction of the steel strip 3 is
Greatly affects the quality of the electroplated layer formed on the surface of the. Therefore, in order to form a high quality electroplating layer on the surface of the steel strip 3, the electroplating solution 4
The relative velocity between the steel strip 3 and the steel strip 3 is constant, and the flow velocity distribution of the electroplating solution 4 is required to be uniform in the width direction of the steel strip 3.

However, the flow velocity distribution of the electroplating solution 4 is difficult to be uniform in the width direction of the steel strip 3 for the following reason. That is, as shown by the arrow in FIG. 11, the electroplating solution ejected from the plating solution ejecting nozzles 7,7 passes through the gap between the steel strip 3 and each of the electrode plates 2,2, and the electrode plates 2,2 After being discharged from the entrance end of the
Clash with. In this way, the electroplating liquid that has collided with the entry-side guide rolls 5, 5 either stays there or flows into the side walls of the electroplating tank 1.

As a result, in the electroplating solution in the electroplating tank 1, a flow in a direction different from the jet flow from the plating liquid jet nozzles 7,7 is generated, and due to this flow, the jets are jetted from the nozzles 7,7. As a result of the disturbance of the flow of the electroplating solution, the flow velocity distribution of the electroplating solution becomes uneven in the width direction of the steel strip 3. In particular, in order to shorten the length of the electroplating tank 1,
Since the inlet side guide rolls 5,5 are arranged close to the electrode plates 2,2, the plating liquid jet flow from the nozzles 7,7 by the electroplating liquid colliding with the inlet side guide rolls 5,5. Has a large effect. Further, the ejection speed of the electroplating solution from the nozzles 7, 7 varies, and the ejected electroplating solution tends to spread outward.

FIG. 12 is a graph showing the difference between the flow velocity of the electroplating solution and the average flow velocity in the width direction of the steel strip. As is clear from FIG. 12, the flow velocity of the electroplating solution has a maximum difference of about ± 10% in the width direction of the steel strip. FIG. 13 is a graph showing the difference between the plating adhesion amount in the width direction of the steel strip and the target adhesion amount. As is clear from FIG. 13, the plating deposition amount at both widthwise end portions of the steel strip is increased by about 10% at the maximum as compared with the target deposition amount. FIG. 14 is a graph showing a warp state in the width direction of the steel strip. As is clear from Fig. 14, the widthwise center of the steel strip is approximately 1.5 mm from both ends.
Warp occurs in the height of.

In order to solve the above-mentioned problems, various studies have hitherto been made, for example, JP-A-59-205496.
As disclosed in Japanese Patent Publication (Kokai), a device (hereinafter referred to as prior art 1) for uniformizing the flow velocity of an electroplating solution flowing on the surface of a steel strip by sealing the side surface of an electrode plate, or an electroplating solution There is known a method of changing the flow rate of the electroplating liquid ejected from the nozzle in the width direction of the steel strip (hereinafter referred to as prior art 2) so that the flow velocity distribution of the steel strip becomes uniform in the width direction of the steel strip. .

[0009]

However, in both of the prior arts 1 and 2 described above, the electroplating solution ejected from the plating solution ejecting nozzles 7, 7 is a pair of electrode plates 2, 2.
As described above, the jetting of the electroplating liquid from the nozzles 7 and 7 is caused by the flow of the electroplating liquid that has collided with the inlet guide rolls 5 and 5, because it is a means that is applied before passing through the space. Flow velocity distribution of the electroplating solution 4 by eliminating the influence of the flow
It cannot be made uniform in the width direction of the steel strip 3.

Therefore, an object of the present invention is to solve the above-mentioned problems and to prevent the flow of the electroplating solution jetted from the plating solution jetting nozzle from being disturbed and to obtain the flow velocity distribution of the electroplating solution of the steel strip. An object of the present invention is to provide a continuous electroplating apparatus that can form a high quality electroplating layer on the surface of a steel strip by making it uniform in the width direction.

[0011]

SUMMARY OF THE INVENTION The apparatus of the present invention includes an electroplating bath for containing an electroplating solution, and a steel strip moving in the electroplating bath substantially parallel to the steel strip. At least one pair of electrode plates sandwiched therebetween and provided on both sides thereof with a predetermined gap, and the steel strip and the at least one pair of electrodes close to the steel strip outlet side end of the at least one pair of electrode plates. A nozzle for jetting a plating solution, which is provided in the width direction of the steel strip toward the gap with each of the plates, for flowing an electroplating solution in the gap in a direction opposite to the moving direction of the steel strip; In the gap between the steel strip and each of the at least one pair of electrode plates in the continuous electroplating apparatus for steel strips, Plating solution suction nozzle for sucking the electroplating liquid discharged from the flow and the entering-side end, and it has the characteristics that are disposed in the width direction of the steel strip.

[0012]

According to the apparatus of the present invention, the steel strip flows in the gap between the steel strip and each of the pair of electrode plates in the direction opposite to the moving direction of the steel strip, and is discharged from the steel strip inlet side end of the electrode plate. The electroplating solution is forcibly sucked by a plating solution suction nozzle provided in the width direction of the steel strip in the vicinity of the inlet side end, and then returned to the plating solution tank. Therefore, the flow of the electroplating solution ejected from the nozzle for ejecting the plating solution is not disturbed by the electroplating solution colliding with the inlet side guide roll, and the flow velocity distribution of the electroplating solution is uniform in the width direction of the steel strip. Then, a high quality electroplating layer can be formed on the surface of the steel strip.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing a first embodiment of the device of the present invention, and FIG. 2 is a schematic plan view thereof. The apparatus of the first embodiment is an example in which the apparatus of the present invention is applied to a horizontal type continuous electroplating apparatus, and as shown in FIGS. 1 and 2, the horizontal type continuous electroplating apparatus uses an electroplating solution 4 The horizontal electroplating tank 1 for containing and the steel strip 3 which is moving horizontally in the electroplating tank 1 are substantially parallel to each other with the steel strip 3 sandwiched therebetween with a predetermined gap above and below the steel strip 3. A pair of arranged electrode plates 2, 2 and a pair of inlet side guide rolls 5 for guiding the steel strip 3 which are provided on the inlet side of the electroplating tank 1 with the steel strip 3 interposed therebetween. 5 and steel strip 3 on the outlet side of electroplating tank 1
A pair of outlet side guide rolls 6 and 6 for sandwiching the steel strip 3 between the steel strips 3 and 1 at the steel strip outlet side ends of the pair of electrode plates 2,2. Pair of electrode plates
Nozzles 7 and 7 for jetting an electroplating solution for flowing an electroplating solution in the direction opposite to the moving direction of the steel strip 3 disposed in the gap with each of the Nos. 2 and 2 It is similar to the conventional device.

In the device of the present invention, a pair of electrode plates
Steel strip 3 near the end of steel strip 2 and 2
The nozzle 8 for sucking the plating liquid for sucking the electroplating liquid discharged from the inlet end by flowing in the gap between the steel plate 3 and each of the electrode plates 2, 2 in the direction opposite to the moving direction of the steel strip 3. 8
Are arranged in the width direction of the steel strip 3.

The nozzles 8 for sucking the plating solution have openings 8
The a and 8a are arranged in the gaps between the steel strip 3 and the electrode plates 2 and 2, respectively, and are arranged close to the inlet side end faces of the electrode plates 2 and 2. At both ends of the plating solution suction nozzles 8,8, conduits 9,9 connected to a plating solution tank (not shown) are connected, and suction pumps 10,10 are provided in the middle of the conduits 9,9. Has been.

The electrode plates 2, 2 are jetted from the plating liquid jet nozzles 7, 7 arranged at the steel strip outlet side ends, and flow in the gap in the direction opposite to the moving direction of the steel strip 3 Most of the electroplating liquid discharged from the steel strip entry side ends of the 2,2 steel strips is sucked by the above-described plating liquid suction nozzles 8,8 and returned to the plating liquid tank.

Therefore, as in the conventional case, the plating solution is jetted from the nozzles 7, 7 and passes through the gap between the steel strip 3 and each of the electrode plates 2, 2 to enter the steel strip entrance side of the electrode plate 2, 2. The amount of the electroplating liquid discharged from the end collides with the inlet-side guide rolls 5, 5 and the amount of staying at the place is reduced, and the electroplating bath 1 smoothly flows into both sides. As a result, the flow of the electroplating solution ejected from the plating solution ejecting nozzles 7, 7 is not disturbed, and the flow velocity distribution of the electroplating solution can be made uniform in the width direction of the steel strip.

FIG. 3 is a schematic perspective view showing an example of the plating liquid suction nozzle 8. As shown in FIG. 3, the opening of the nozzle 8 for sucking the plating solution has a first opening 8b, 8b and a second opening 8c, in which the opening area gradually decreases from both end sides toward the central side. 8c and the third opening 8d. Therefore, the amount of the electroplating liquid sucked from the plating liquid suction nozzle 8 is controlled in the width direction of the steel strip, and the central portion thereof is small and both end portions thereof are large.

FIG. 4 is a schematic plan view showing another example of the plating liquid suction nozzle 8. As shown in FIG. 4, the plating liquid suction nozzle 8 is divided by a plurality of partition plates 11 into a plurality of chambers 11a, 11b, 11c, 11d and 11e in the width direction of the steel strip. A branch pipe 13 having a flow rate adjusting valve 12 is connected to each of the chambers 11a, 11b, 11c, 11d, 11e, and each branch pipe 13 is connected to a conduit 9, 9 provided with a pump 10. Therefore, the amount of the electroplating liquid sucked from the plating liquid suction nozzle 8 is controlled in the width direction of the steel strip by adjusting the flow rate adjusting valve 12.

FIG. 5 is a schematic vertical sectional view showing a second embodiment of the device of the present invention. The apparatus of the second embodiment is an example in which the apparatus of the present invention is applied to a so-called liquid cushion cell type horizontal continuous electroplating apparatus, in which the electroplating solution is not contained in the horizontal electroplating tank. ,
The plating liquid suction nozzles 8,8 are close to the inlet side ends of the pair of electrode plates 2,2, and the openings 8a, 8a are formed in the steel strips 3 and 1 respectively.
It is arranged so as to come into contact with the gap between each of the pair of electrode plates 2,2, and is ejected from the plating solution ejecting nozzle 7,7, and the steel strip 3 and each of the pair of electrode plates 2,2 are ejected. The apparatus differs from the apparatus according to the first embodiment in that all the electroplating liquid flowing through the gap and discharged from the steel strip inlet side ends of the electrode plates 2, 2 is sucked.

FIG. 6 is a schematic vertical sectional view showing a third embodiment of the device of the present invention. The apparatus of the third embodiment is an example in which the apparatus of the present invention is applied to a vertical continuous electroplating apparatus, and as shown in FIG. 6, the vertical continuous electroplating apparatus contains an electrogalvanizing solution 4. A vertical electroplating tank 14 for guiding the steel strip 3 vertically into the plating tank 14 downward, and an inlet side guide roll 15 disposed above the steel strip inlet side of the plating tank 14. Plating tank 14
A sink roll 16 arranged in the plating tank 14 for inverting the moving direction of the steel strip 3 guided inward, and for guiding the steel strip 3 vertically from the plating tank 14 upward. Of the steel strip on the steel strip outlet side of the plating tank 14 and the inlet side guide roll 17
Between the 15 and the sink roll 16, substantially parallel to the steel strip 3 moving downward in the plating tank 14,
A pair of first electrode plates 18 and 18 sandwiching the steel strip 3 between them with a predetermined gap therebetween, and a sink roll 16
Substantially parallel to the steel strip 3 moving upward in the plating tank 14 between the outlet guide roll 17 and
A pair of second electrode plates 19 and 19 and a pair of first electrode plates 18 and 1 sandwiching the steel strip 3 between them and leaving a predetermined gap therebetween.
Electroplating in the opposite direction to the moving direction of the steel strip 3 is arranged at the steel strip outlet end of 8 toward the gap between the steel strip 3 and each of the first electrode plates 18 and 18. Nozzles 20, 20 for ejecting the first plating liquid for flowing the liquid,
At the steel strip outlet side end of the second electrode plate 19,19, which is arranged toward the gap between the steel strip 3 and each of the second electrode plates 19,19, the moving direction of the steel strip 3 The nozzles 21 and 21 for ejecting the second plating solution for flowing the electroplating solution in the opposite direction.

In the device of the present invention, the first electrode plate 1
Proximity to the steel strip inlet side end of 8, 18 flows in the gap between the steel strip 3 and each of the first electrode plates 18, 18 in the direction opposite to the moving direction of the steel strip 3, The first plating solution suction nozzles 22,22 for sucking the electroplating solution discharged from the steel strip 3 are arranged in the width direction of the steel strip 3, and the steel strip discharge of the pair of second electrode plates 19,19. An electroplating solution discharged from the outlet end flows near the side end in the gap between the steel strip 3 and each of the second electrode plates 19 and 19 in the direction opposite to the moving direction of the steel strip 3. The second plating solution suction nozzles 23, 23 for sucking the steel strip are arranged in the width direction of the steel strip 3.

At both ends of the first plating solution suction nozzles 22 and 22 and the second plating solution suction nozzles 23 and 23, conduits connected to a plating solution tank via a suction pump not shown are connected, First electrode plate 18, 18 and second electrode plate 1
Most of the electroplating liquid discharged from the outlet end of 9,19 is returned to the plating liquid tank.

Therefore, the nozzles 20, 20 for ejecting the first plating solution
Of the electroplating liquid ejected from the steel strip 3 and flowing in the gap between the steel strip 3 and each of the first electrode plates 18 and 18 and discharged from the steel strip inlet side end of the first electrode plate 18 and 18 It is sucked by the plating liquid suction nozzles 22,22, and the second
Electricity ejected from the plating solution ejecting nozzles 21,21, flowing in the gap between the steel strip 3 and each of the second electrode plates 19,19, and discharged from the steel strip inlet side end of the second electrode plate 19,19. Most of the plating solution is sucked by the second plating solution suction nozzles 23, 23. As a result, the nozzle for jetting the first plating solution
There is no turbulence in the flow of the electroplating liquid ejected from the nozzles 20, 20 and the second plating liquid ejecting nozzles 21, 21,
The flow velocity distribution of the electroplating liquid can be made uniform in the width direction of the steel strip.

FIG. 7 shows an average flow velocity of the electroplating solution in the width direction of the steel strip when the steel strip is electroplated by the apparatus of the first embodiment of the present invention shown in FIGS. 1 and 2. 9 is a graph showing a difference with a flow velocity, FIG. 8 is a graph showing a difference between a plating deposition amount in a width direction of a steel strip and a target deposition amount, and
FIG. 9 is a graph showing the state of warpage in the width direction of the steel strip. 7 to 9, the black circles show the case where the apparatus of the present invention is used, and the white circles show the case where the conventional apparatus without the plating solution suction nozzle is used.

As is apparent from FIGS. 7 to 9, when the apparatus of the present invention is used, there is almost no difference in the flow velocity of the electroplating solution in the width direction of the steel strip, and the plating adhesion in the width direction of the steel strip. The amount is almost uniform, and the steel strip is not warped in the width direction.

A plating liquid suction nozzle capable of controlling the amount of the electroplating liquid sucked in the width direction of the steel strip as shown in FIG. 3 or 4 is used, and at least the steel strip and the steel strip are used. The flow velocity of the electroplating solution flowing in the gap between the pair of electrode plates in the direction opposite to the moving direction of the steel strip and its flowing direction were measured at a plurality of points in the width direction of the steel strip, and based on the measurement results. Then, the suction amount of the electroplating liquid by the plating liquid suction nozzle may be controlled in the width direction of the steel strip.

[0028]

As described above, according to the present invention,
There is no turbulence in the flow of the electroplating solution ejected from the plating solution ejecting nozzle, and the flow velocity distribution of the electroplating solution is uniform in the width direction of the steel strip, resulting in excellent quality on the surface of the steel strip. An industrially useful effect that an electroplated layer can be formed is brought about.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a first embodiment of the device of the present invention.

FIG. 2 is a schematic plan view of the device of FIG.

FIG. 3 is a schematic perspective view showing an example of a plating liquid suction nozzle.

FIG. 4 is a schematic plan view showing another example of a plating liquid suction nozzle.

FIG. 5 is a schematic vertical sectional view showing a second embodiment of the device of the present invention.

FIG. 6 is a schematic vertical sectional view showing a third embodiment of the device of the present invention.

FIG. 7 is a graph showing the difference between the flow velocity of the electroplating solution in the width direction of the steel strip and the average flow velocity when the steel strip is electroplated by the apparatus according to the first embodiment of the present invention.

FIG. 8 is a graph showing a difference between a plating deposit amount in a width direction of the steel strip and a target deposit amount when the steel strip is electroplated by the apparatus according to the first embodiment of the present invention.

FIG. 9 is a graph showing a state of warpage in the width direction of the steel strip when the steel strip is electroplated by the apparatus according to the first embodiment of the present invention.

FIG. 10 is a schematic vertical sectional view of a conventional horizontal type continuous electroplating apparatus.

11 is a schematic plan view of FIG.

FIG. 12 is a graph showing the difference between the flow velocity of the electroplating solution in the width direction of the steel strip and the average flow velocity when the steel strip is electroplated by the conventional apparatus.

FIG. 13 is a graph showing a difference between a plating deposition amount in a width direction of the steel strip and a target deposition amount when the steel strip is electroplated by the conventional apparatus.

FIG. 14 is a graph showing the state of warpage in the width direction of a steel strip when the steel strip is electroplated by a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electroplating tank 2 Electrode plate, 3 Steel strip, 4 Electroplating liquid, 5 Inlet side guide roll, 6 Outlet side guide roll, 7 Plating liquid jet nozzle, 8 Plating liquid suction nozzle, 9 Conduit, 10 Pump, 11 Partition plate, 12 flow control valve, 13 branch pipe, 14 vertical electroplating tank, 15 inlet side guide roll, 16 sink roll, 17 outlet side guide roll, 18 1st electrode plate, 19 2nd electrode plate, 20 1st plating Liquid jet nozzle, 21 2nd plating liquid jet nozzle, 22 1st plating liquid suction nozzle, 23 2nd plating liquid suction nozzle

Claims (1)

[Claims] 1. An electroplating bath for containing an electroplating solution, and a steel plate which is moving in the electroplating bath, and the steel strip is sandwiched between the steel strip and a predetermined gap on both sides thereof. The at least one pair of electrode plates provided in the vicinity of the steel strip outlet end of the at least one pair of electrode plates, and facing the gap between the steel strip and each of the at least one pair of electrode plates, In a continuous electroplating apparatus for a steel strip, which is provided in the width direction of a steel strip, for flowing an electroplating solution in the gap in the direction opposite to the moving direction of the steel strip, and a nozzle for jetting a plating solution Flowing in a gap between the steel strip and each of the at least one pair of electrode plates proximate the steel strip entry side ends of the at least one pair of electrode plates and discharged from the entry side ends. That the plating solution suction nozzle for sucking an electroplating solution, characterized in that it is arranged in a width direction of the steel strip, a continuous electroplating apparatus of the steel strip.