JPH0160558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a vertical electroplating device for plating metal plates such as steel plates.

(Technical background of the invention and its problems) Vertical electroplating equipment requires less installation space and has better ability to remove gas bubbles generated by the insoluble anode than general horizontal electroplating equipment.
In addition, there are advantages such as uniform plating quality on the front and back sides. The general configuration of a vertical electroplating device is as shown in FIG. 1, in which a plurality of vertical electroplating tanks 1, 1, in the illustrated example, two vertical electroplating tanks 1, 1 are arranged in series. An energizing roll 5 is disposed above the plating tank at a considerable distance from the plating solution, and is configured to guide a passing material 4 such as a steel plate and energize the passing material 4. A hold-down roll 6 for bringing the passing material 4 into close contact with the current-carrying roll 5 is provided opposite to the current-carrying roll 5. On the other hand, in the plating tank 1, a sink roll 2 for guiding the threading material 4 and an anode 7 facing the descending portion and rising portion of the threading material 4 are arranged.

However, the conventional vertical electroplating apparatus as described above has the following problems. That is, firstly, since the energizing roll has a large diameter, the manufacturing cost and repair cost of the energizing roll increases.

The current carrying capacity of the current carrying roll depends on the diameter of the current carrying roll and the contact pressure between the current carrying roll and the metal plate. Further, a predetermined diameter is required to prevent work hardening of the metal plate. In consideration of these points, conventionally, a large diameter energized roll of about 600 to 1500 mmφ has been used.

However, in recent electrogalvanizing lines,
There is a tendency for plating baths to become more corrosive. In other words, when using an insoluble anode, the bath temperature is increased and the pH of the bath is lowered to promote dissolution of the metal powder or metal lump to be replenished. Even in these cases, chloride baths are increasingly being used to improve electrical conductivity. As a result, the plating bath becomes highly corrosive, and in order to make the current-carrying roll able to withstand this corrosive condition, the material of the current-carrying roll has to be changed from the conventional material.
SS41 class steel rolls have been upgraded from Ni-plated or Cr-plated rolls to those lined with Hastelloy or titanium. As a result, manufacturing costs and repair costs for energized rolls tend to rise.

On the other hand, the current carrying capacity of the above-mentioned current-carrying rolls can be made smaller by increasing the contact pressure with the carrying material and by adopting an internal water-cooling system for the current-carrying roll. ,
It has been improved to about 20 to 40 KA per bottle.
However, in a vertical plating tank, the minimum diameter of the current-carrying roll is determined by the dimensions of the anode system, and the diameter must be increased as the plate thickness increases. . For this reason, in the vertical plating apparatus, there is a limit to the miniaturization of the energizing roll, and in the end, it is necessary to use an expensive energizing roll with a large diameter.

The second problem is that since the current-carrying roll is located below the carrying material, not only does it take a lot of effort to replace the roll, but it is also difficult to maintain. Conventionally, the current-carrying roll is located below the plate-carrying material, as shown in FIG. Therefore, when replacing the energizing roll in the case where an arc spot occurs or a foreign object gets caught and the energizing roll is damaged, it is necessary to stop the line, cut the threaded material, and then remove it. There was a problem in that it had to be removed, which required a lot of effort and time.

(Objective of the Invention) The present invention solves the problems of the prior art as described above at once.The purpose of the present invention is to reduce equipment costs and repair costs, facilitate maintenance, and improve operability. It is an object of the present invention to provide an excellent vertical electroplating device which does not generate arc spots.

(Structure of the Invention) The present invention basically consists of providing a large-diameter deflector roll in place of the conventional large-diameter current-carrying roll, thereby allowing the deflector roll to guide the passing material into the plating tank. By arranging the current-carrying roll at a position opposite to the outer side of the deflector roll through the sheet-carrying material and energizing the sheet-carrying material, the diameter of the current-carrying roll can be reduced, thereby reducing the manufacturing cost of the current-carrying roll. This also aims to reduce repair costs and facilitate maintenance of the energized roll. Furthermore, the deflector roll is made of a material with good thermal conductivity and is cooled using a refrigerant to prevent the occurrence of arc spots.

(Specific Example of the Invention) The present invention will be explained based on the schematic diagram shown in FIG.

The vertical electroplating apparatus of the present invention is basically the same as the conventional example shown in FIG. 1 with respect to the internal structure of the plating tank 1. A plurality of plating tanks 1, 1 are connected in tandem, each plating tank 1 is filled with plating liquid 3, and a sink roll 2 is provided at a lower position in the plating tank to control the passing of the material in the plating tank 1. 4
Furthermore, an anode 7 is provided facing the threading material 4 along the threading direction of the threading material 4 at the descending and rising portions of the threading material 4 guided in the plating tank. It is being

The vertical electroplating device of the present invention is different from the conventional example shown in FIG. A small-diameter current-carrying roll 5' is provided opposite the deflector roll.

Here, the deflector roll 8 is, for example,
A steel roll coated with rubber or the like that is not corroded by the plating solution 3, or preferably a roll made of a material having chemical resistance and good thermal conductivity, is used. The diameter of the deflector roll 8 is determined by taking into consideration the dimensions of the anode system, the adhesion of the threading material, work hardening, etc., but it is generally 600 to 1500.
mmφ is appropriate.

The deflector roll 8 is preferably disposed at a position above the plating tank that is a predetermined distance away from the plating liquid 3. Generally, the shorter the distance between the energization position and the anode position, the smaller the power loss based on the specific electrical resistance of the plate passing material. Therefore, regarding the problem of power loss, it is desirable to place the current supply position as close to the anode as possible, and it is advantageous for the deflector roll to be positioned very close to the plating solution or immersed in the plating solution. The applicant of the present application previously disclosed in Japanese Patent Application No. 57-85799 that when the deflector roll is disposed half-immersed in the plating liquid, the distance between the anode and the energized position can be shortened, and as a result, It is disclosed that it is possible to reduce power loss due to the specific electrical resistance of the threaded material. However, when the deflector roll is provided close to the plating solution or immersed in the plating solution, the following problem arises and it is not practical.

(1) It is not possible to secure installation space for the equipment attached to the plating tank. That is, in the case of the soluble anode method, a space is required for installing an anode bridge that suspends a rectangular anode bar. In addition, in recent years, plating methods that use insoluble anodes have become popular, but when using insoluble anodes, in order to equalize the current distribution in the width direction of the threaded material, the plating method shown in Figure 3 is usually used. An edge masking device is provided. When installing this masking device, a device for moving the masking material 9 in the board width direction is installed between the anode 7 and the deflector roll 8, and
Threaded material end position detection device 10, for example, optical, magnetic,
It is necessary to install a pneumatic detector between the upper part of the masking material 9 and the deflector roll 8. Also,
It is also common on high-speed lines to install a ringer roll to squeeze out the plating solution that adheres to the strip moving from the electrolytic cell to the deflector roll. However, deflector roll 8
In the case where the plating tank is placed close to the plating tank or immersed in the plating solution, it is not possible to secure installation space for the above-mentioned incidental equipment, which is impractical.

(2) There is a problem of plating liquid splashing onto peripheral equipment.
That is, especially during high-speed sheet passing, the deflector roll 8 pumps up the plating liquid 3, producing a large amount of splash, and causing droplets to adhere to peripheral equipment such as edge masking equipment, various electrical instrumentation parts, conductive wires, etc., causing serious damage. May cause corrosion damage to equipment.

Considering the above, the deflector roll 8 is spaced apart from the plating tank 1 and the plating liquid 3 to an extent that allows the installation of plating tank ancillary equipment, and also minimizes power loss due to the specific electrical resistance of the threaded material. It is preferable that the plate be located as close as possible to the plating solution. In other words, the installation position of the deflector roll 8 is such that the core (center line) of the deflector roll is 400 mm from the surface of the plating liquid.
A position approximately 2000mm apart is appropriate, especially
Preferably, the positions are approximately 600 to 1200 mm apart.

On the other hand, the energizing roll 5' may be a conventional steel roll lined with Hastelloy, but its diameter is 500 to 200 mmφ, especially considering the cost reduction of the energizing roll itself, which is one of the objectives of the present invention. 400
~300mmφ is desirable.

At least one energizing roll 5', preferably one pair, or a plurality of energizing rolls 5' are provided for one deflector roll 8. Energizing roll 5'
The arrangement position thereof is a position facing the deflector roll 8 via the threading material 4, and preferably a side position of the deflector roll 8 as shown in FIG. This is because the length from the energization position to the anode 7 is made as short as possible, thereby lowering the specific electrical resistance of the plate passing material 4 and reducing power loss. When one pair or a plurality of energizing rolls 5' are provided, appropriate contact between the energizing rolls 5' and the plate material 4 can be ensured.
The energizing rolls 5' are arranged so as to be in contact with the threading material 4 with appropriate pressing force, but in order to further ensure the pressing force against the threading material 4, for example, each energizing roll 5' It is also possible to provide a pressing roll (not shown) or the like.

As described above, in the present invention, the deflector roll 8 is formed from a material that is chemically resistant and has good thermal conductivity. Furthermore, a refrigerant such as cold water, fluorocarbon gas, etc. is passed through the interior of the deflector roll 8 to cool the threaded material 4, thereby lowering the contact temperature between the energizing roll 5' and the threaded material 4. This is to suppress the occurrence of arc spots between the plate material 4 and the current-carrying roll 5', and to prevent the quality of the plated product from deteriorating due to arc spots. To explain in more detail, in general, in a continuous plating line for metal strips, sparks or arc spots are generated between the running metal strip and the current-carrying roll, causing welding surface flaws on the surfaces of the metal strip and the current-carrying roll. The phenomenon that occurs can be seen. As a result, the value of the plating product is impaired, the yield is lowered, or the current-carrying roll wears out more quickly, shortening its lifespan. Although the cause of this arc spot generation is not necessarily clear from an academic point of view, it is known that it can be improved by internally cooling the current-carrying roll. However, in recent years, as the plating operating current density has increased, an increase in the frequency of arc spot occurrence due to a rise in the temperature of the current-carrying contact has become a problem. In the present invention, in addition to cooling the current-carrying roll 5', the occurrence of arc spots is solved by cooling the deflector roll 8 by passing a refrigerant into the large-diameter deflector roll 8 made of a material with good electrical conductivity. This is prevented by effectively cooling the threading material 4 from the front and back surfaces, thereby lowering the temperature at the contact point between the current-carrying roll 5' and the threading material 4.

(Effects of the Invention) As described above, according to the present invention, since the deflector roll is arranged inside the threaded material and the energized roll is arranged on the outside, the diameter of the energized roll can be reduced, which makes it more economical. Not only is this convenient, but also when it becomes necessary to replace the energizing roll due to the occurrence of indentation flaws, the energizing roll can be removed upwards without cutting the threaded material and reinstalled within a short time. Can be done. Further, if the degree of the flaw is slight, the surface of the current-carrying roll can be cleaned by polishing with a grinder or the like even during line operation. In addition, since the energizing roll is placed outside the plate material, there is less chance of plating liquid splashes adhering to it. Therefore, the energizing roll can be placed close to the plating liquid, for example, on the side of the deflector roll. can. In this case, power loss due to the specific resistance of the threaded material can be minimized. Furthermore, when the deflector roll is formed from a chemically resistant and highly thermally conductive material, such as Hastelloy C, and the inside of the deflector roll is cooled by water cooling or the like,
Even when operating at a high current density of 100 to 400 A/dm ² , the frequency of arc spot occurrence can be significantly reduced to, for example, about half of that without cooling.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional vertical electroplating device.
FIG. 2 is a schematic diagram of the vertical electroplating device of the present invention;
FIG. 3 is a schematic perspective view of the edge masking device. 1... Plating tank, 2... Sinking roll, 3... Plating liquid, 4... Threading material, 5, 5'... Current roll, 6... Hold down roll, 7... Anode, 8... Deflector roll, 9... Masking material, 10... Threaded material end position detection device.

Claims (1)

[Claims] 1. A deflector roll for guiding the metal plate to be plated into a vertical electroplating tank is provided above the plating tank at a predetermined distance from the plating tank, the deflector roll is made of a material with good thermal conductivity, and a refrigerant is supplied to the deflector roll. 1. A vertical electroplating apparatus characterized in that at least one current-carrying roll is provided facing the deflector roll with a metal plate to be plated in between.